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Yin, Weiwei. "A Mathematical Model of the Sleep-Wake Cycle." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14508.
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The daily sleep-wake cycle usually consists of three distinct states: wakefulness, non-rapid-eye-movement (NREM) and rapid-eye-movement (REM). The process of switching between different states is complex, but a common assumption is that it is regulated primarily by two processes (the circadian and the homeostatic process) via reciprocal interactions of several downstream neuron groups. These interactions not only result in often rapid transitions from one state to another, but also allow for a certain degree of bi-stability that locks the organism in a given state for some while before it switches back. In order to better understand how the behavioral states are regulated by different neuron groups, I describe how to use the S-system method for the development of a mathematical model consisting of two phases. The first phase covers the switch between wakefulness and sleep, which is controlled by the interactions between wake- and sleep-promoting neurons, whereas the second phase addresses the generation of NREM-REM alternation, which is believed to be regulated by REM-OFF and REM-ON neurons. In this set-up I interpret the circadian rhythm as external input and homeostatic regulation as a feedback controller. Both open-loop and closed-loop forms of the two-phase model are investigated and implemented. Discharging activities of the corresponding neuron groups and the switches of behavioral states are shown in the simulation results, from which we can easily identify the basic roles of wake- and sleep-promoting neurons, REM-OFF and REM-ON neurons. The special regulatory function of the neuropeptide orexin is also tested by simulation.
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Grow, Brian J. Sullivan Matthew C. "Assessing the effect of shipboard motion and sleep surface on sleep effectiveness." Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Dec/09Dec%5FGrow.pdf.
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Thesis (M.S. in Human Systems Integration)--Naval Postgraduate School, December 2009.<br>Thesis Advisor(s): Miller, Nita Lewis. Second Reader: McCauley, Michael E. "December 2009." Description based on title screen as viewed on January 26, 2010. Author(s) subject terms: Sleep Efficiency, Sleeping Surface, Acceleration, Motion Effects on Sleep, Actigraphy, Sleep Quality, Shipboard Sleep. Includes bibliographical references (p. 83-87). Also available in print.
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Webster, Harry 1947. "The role of cholinergic neurons of the dorsolateral pontomesencephalic tegmentum in sleep-wakefulness states /." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75890.
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Pontomesencephalic tegmental cholinergic neurons were destroyed in cats by local injections of kainic acid in order to assess the role of these neurons in sleep-wakefulness states and in the defining variables of these states: EEG (electroencephalographic) and EMG (electromyographic) amplitude, PGO (ponto-geniculo-occipital) spike rate, REMs (rapid eye movements) and (OBS) olfactory bulb spindles. Loss of cholinergic innervation to forebrain and brainstem structures was also assessed by histochemistry. Histological and histochemical analysis of the brains after the lesion showed a major destruction of the pontomesencephalic cholinergic neurons and a major loss of innervation to thalamic nuclei and brainstem regions, including the reticular formation. Whereas the states of waking and slow wave sleep were relatively unaffected, paradoxical sleep (PS) was reduced or eliminated immediately following the lesions. Two to three weeks later, incipient PS-like episodes returned with a reduced PGO spike rate and REMs, and an elevated EMG amplitude, marking the loss of muscle atonia. Such results suggest pontomesencephalic cholinergic neurons and their projections to thalamic and brainstem regions are important for the expression of PS and its defining variables.
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Eder, Derek N. "A naturalistic study of sleep regulation in seasonal affective disorder : SAD, asleep, and unresponsive /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/9072.
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D'Agnese, Mattiangelo. "Sleep-wake cycle: a new analysis for the two-step process model." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19307/.
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Il ciclo sonno-veglia é oggetto di studio per molti scienziati e matematici da più di trent’anni ma nonostante ciò molti quesiti non trovano ancora una risposta. Capire i meccanismi e le dinamiche del ciclo sonno-veglia è un problema molto importante perché le sue alterazioni possono avere conseguenze significative sulla salute umana.
In questo lavoro viene presentato un modello matematico, con basi biologiche, del ciclo sonno-veglia. La principale novità rispetto ai modelli precedenti è l’utilizzo di un accurato modello neuronale, il modello di Hodgkin-Huxley, che permette di descrivere il sistema usando connessioni sinaptiche realistiche.
Crediamo fermamente che questo argomento meriti una investigazione dettagliata, non solo per il contenuto fisico e matematico, ma anche per il suo potenziale impatto sulla ricerca nel campo della sanità.
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Yu, Xiao. "Histamine at the intersection of the sleep-wake cycle and circadian rhythms." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/26596.
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Histamine is central in sleep-wake regulation. First, I mapped the distribution of histamine producing neurons in the adult brain using genetic approaches. Second, to further explore the histaminergic system, I found that a local circadian clock regulates the expression of histidine decarboxylase (HDC), the enzyme producing histamine in hypothalamic neurons. The level of this enzyme varies with time of day and is up-regulated by sleep deprivation. I disrupted this local clock by using HDC-Cre recombinase by deleting BMAL1, the transciption factor central to circadian rhythms, selectively in histaminergic neurons, generating HDC-Bmal1 mice. Hdc gene expression in HDC-Bmal1 mice showed a disrupted 24-hour rhythm. This greatly affected natural sleep and reduced recovery sleep after sleep deprivation. Third, the HDC-neurons contain GABA. To understand the role of this GABA, I used different AAVs carrying shRNAs to deliver into the brain to knock down vesicular GABA transporter (vGAT) in histaminergic neurons. Reducing vGAT in HDC-neurons increased general activity and wakefulness in mice; moreover, these GABA in HDC-neurons contributed to recovery sleep after sleep deprivation. To further investigate the mechanism, we conducted an optogenetic method by delivering Channelrhodopsins (ChR2) into the HDC-neurons. We found that photostimulating tuberomamillary nucleus (TMN) fibers in neocortex and striatum triggered GABA release. Thus the decrease of ambient GABA might contribute to the phenotype that we observed in HDC-vGAT knock down mice. In summary, I identified a local 'histaminergic clock' that regulates HDC levels, and is necessary for maintaining appropriate sleep-wake cycle architecture as well as sleep homeostasis. I also found GABA produced by HDC-neurons is necessary for regulating the normal behavioral state.
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Assadzadeh, Sahand. "Large-Scale Brain Dynamics: Plasticity and States of Consciousness." Thesis, University of Sydney, 2018. https://hdl.handle.net/2123/23708.
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The brain is a complex system that exhibits rich multiscale dynamics. Large-scale activity in this system are readily observable by a range of methods including electroencephalography (EEG). Changes to the global state of the brain, including arousal states such as wakeful consciousness and its temporary disappearance with sleep onset, are associated with major changes in brain electric activity as seen in the EEG. However, the purpose of the sleep state, which involves widespread changes in activity that occur in the brain, remains a matter of debate, especially because very little content of the brain activity that occurs during sleep directly enters conscious awareness. Analysis of EEG using modeling approaches has been highly successful at relating large scale brain physiology to experimental observations. In particular, physiologically based modeling addresses significant issues that commonly arise in high-dimensional models, by constraining each parameter on the basis of experimental data, and by providing a physiologically meaningful interpretation of all model parameters. One class of brain models is based on neural field theory, which averages the properties of neurons over short temporal and spatial scales to form continuous fields that represent neural activity. These models are ideally suited to EEG comparison and analysis because the EEG reflects the combined activity of millions of individual neurons. This thesis uses an established neural field model of the brain to investigate large-scale synaptic plasticity over a range of brain states. In particular, the model is used to investigate the synaptic homeostasis hypothesis, which postulates that sleep is necessary for long-term synaptic stability. The same biophysical model is also used to estimate physiological quantities in various disorders of consciousness.
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Reid, Kathryn J. "Measuring adaption to shiftwork /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phr3561.pdf.
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Martin, Jennifer Lynn. "Aging and sleep in schizophrenia patients and normal comparison subjects : subjective reports and objective findings /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3049676.
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Haynes, Patricia L. "Circadian impact of psychosocial factors in depression /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2003. http://wwwlib.umi.com/cr/ucsd/fullcit?p3094609.
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Rosa, Dayane Eusenia 1985. "Relação do ciclo vigília-sono com alterações de glicemia e pressão arterial em idosos atendidos pela Estratégia Saúde da Família = The relationship of sleep-wake cycle with glucose and blood pressure variations in elderly people attended by Health Family Strategy." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310920.
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Orientador: Maria Filomena Ceolim<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas<br>Made available in DSpace on 2018-08-21T06:44:31Z (GMT). No. of bitstreams: 1
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Previous issue date: 2012<br>Resumo: A hipertensão arterial sistêmica (HAS) e o diabetes mellitus (DM) são doenças crônicas que se encontram entre as principais causas de mortalidade no mundo, de acordo com a Organização Mundial de Saúde. As perturbações do sono, que são prevalentes na idade avançada, podem desencadear uma série de modificações neuroendócrinas, dentre elas intolerância à glicose e alterações nos níveis de produção de hormônios, as quais podem provocar distúrbios na pressão arterial e na glicemia. Este trabalho teve como objetivo relacionar valores de pressão arterial e níveis glicêmicos com a duração e a qualidade do sono nesses idosos. Participaram 42 idosos (60 anos ou mais) de ambos os sexos, com diagnóstico de HAS e/ou DM, cadastrados na Estratégia da Saúde da Família (ESF). A coleta de dados englobou duas etapas: Etapa 1. Coleta de dados sociodemográficos e clínicos; preenchimento, pelos idosos, de Diário de Sono durante 10 dias consecutivos; monitoramento de pressão arterial e glicemia capilar, em horários distintos (manhã e tarde), por três dias consecutivos, pelo pesquisador, no domicílio do idoso. Etapa 2. 30 dias após a Etapa 1, compreendeu o preenchimento do Índice de Qualidade do Sono de Pittsburgh (PSQI) e a dosagem sérica de hemoglobina glicada em jejum. Os dados foram analisados com estatística descritiva, teste de Correlação de Postos de Spearman, teste de Mann-Whitney e análise de modelos lineares de efeitos mistos. Os participantes (76,2% mulheres) tinham idade média de 66,8 anos (desvio padrão 5,6) e 4,3 anos de escolaridade (desvio padrão 2,2). A duração média do sono, segundo o Diário, foi de sete horas e 18 minutos, e de sete horas e quatro minutos segundo o PSQI. A qualidade do sono, segundo o PSQI, mostrou-se boa para 50% dos idosos e ruim para os demais, com média de 6,4 pontos (desvio padrão 4,0). As variações da qualidade e da duração do sono, ao longo dos dias e horários, não se mostraram significativamente associadas com as variações de pressão arterial e glicemia capilar. Porém, houve tendência estatística a essa associação entre a variação da qualidade (p=0,057) e da duração do sono (p=0,068) e os valores de pressão arterial. Encontrou-se fraca correlação entre os valores da hemoglobina glicada e o escore global do PSQI, sugerindo tendência a essa associação (r de Spearman=0,30, p=0,054). O Componente 5 do PSQI, que avalia os transtornos do sono noturno, apresentou correlação significativa com os valores de hemoglobina glicada (r de Spearman=0,40, p<0,05). Os idosos deste estudo apresentaram, em maioria, duração adequada e avaliação satisfatória da qualidade do sono, bem como controle satisfatório da glicemia e de pressão arterial. Esses aspectos podem ter contribuído para que não fossem encontradas associações significativas entre as variáveis. No entanto, os resultados apontam para a relevância do acompanhamento das características do sono dos idosos nos programas Estratégia de Saúde da Família<br>Abstract: Hypertension (HBP) and Diabetes Mellitus (DM) are chronic diseases that are among the leading causes of mortality worldwide, according to World Health Organization. Sleep disturbances, which are prevalent in old age, can trigger a series of neuroendocrine changes, among them glucose intolerance and altered levels of hormones production, which can cause alterations in blood pressure and blood glucose. This work aimed to identify relationships between blood pressure and glucose levels and variations in sleep duration and sleep quality. Participants in the study were 42 elderly (60 years or more) of both genders, with a diagnosis of HBP and DM, attended at the Family Health Strategy (FHS) in a city of the State of Goias, Brazil. Data collection comprised two steps: Step 1. Collection of sociodemographic and clinical data; the completion, by the elderly, of a Sleep Diary for 10 consecutive days; monitoring of blood pressure and blood glucose by the researcher, at two different time points (morning and afternoon) for three consecutive days, at elderly home. Step 2. Conducted 30 days after Step 1, included the completion of the Pittsburgh Sleep Quality Index (PSQI) and sampling of serum fasting glycated hemoglobin. Data were analyzed with descriptive statistics, Spearman's Rank Correlation test, Mann-Whitney test and analysis of linear mixed effects models. Participants (76.2% women) had a mean age of 66.8 years (SD 5.6) and 4.3 years of schooling (SD 2.2). Sleep length, according to Sleep Diary, was of seven hours and eighteen minutes, and seven hours and four minutes according to PSQI. Sleep quality, according to PSQI, was good for 50% of the elderly and poor for the others, with a mean score of 6.4 points (SD 4.0). Variations in sleep length and quality, along the different days and time points, were not significantly associated with changes in blood pressure and capillary blood glucose. However, there was a trend to this association between variations in sleep quality (p=0.057) and sleep length (p=0.068) and blood pressure values. A weak correlation was found between the values of glycated hemoglobin and the global PSQI score, suggesting a trend to this association (Spearman r=0.30, p=0.054). Component 5 of PSQI, which assesses night sleep disorders, was significantly correlated with glycated hemoglobin levels (Spearman r=0.40, p<0.05). The elderly in this study had, at most, appropriate duration and satisfactory assessment of sleep quality, as well as satisfactory control of blood glucose and blood pressure. These aspects may have contributed to that significant associations between variables were not found. However, the results point to the importance of monitoring the sleep characteristics of elderly in the programs of the Family Health Strategy<br>Mestrado<br>Enfermagem e Trabalho<br>Mestra em Ciências da Saúde
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Jouvencel, Aurore. "Cycle veille-sommeil et vulnérabilité cérébrale de la personne âgée : étude d'imagerie et d'actimétrie." Electronic Thesis or Diss., Université Paris sciences et lettres, 2024. http://www.theses.fr/2024UPSLP027.
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L'objectif principal de cette thèse était de déterminer comment les perturbations du cycle veille-sommeil et du sommeil peuvent constituer des facteurs de vulnérabilité cérébrale. Nous avons utilisé une combinaison de mesures écologiques du cycle veille-sommeil et de l'imagerie multimodale récoltées sur des cohortes de volontaires Français et Néerlandais afin d'appréhender de manière globale la relation entre le cycle veille-sommeil et la santé cérébrale.Nous avons d'abord montré la complémentarité des méthodes objective et subjective (actimétrie et PSQI) pour évaluer la qualité et la durée du sommeil dans un échantillon de 1440 participants de la Rotterdam Study. Alors qu'en moyenne, la qualité subjective du sommeil était bonne (3.5 ± 3.3), la qualité et la quantité objectives du sommeil étaient mauvaises avec une efficacité de sommeil de 76.0% ± 8.3 et une durée de 6h13 ± 0h54. En étudiant les liens entre la qualité de sommeil et la fréquence de vertiges auto-rapportée, nous avons pu observer qu'une mauvaise qualité subjective du sommeil était significativement liée à la prévalence des vertiges alors qu'aucun lien n'a été observé avec les mesures objectives du sommeil (Hoepel, Jouvencel et al., 2023).Puis nous avons démontré que la variabilité intra-individuelle de la qualité objective du sommeil de début de nuit était liée à une plus grande accumulation de protéines amyloïde béta dans le cerveau de sujets âgés sans trouble cognitif (Jouvencel et al., 2023). Ces résultats pourraient résulter d'une moindre efficacité de clairance du système glymphatique chez ces sujets au sommeil perturbé. Enfin, en évaluant l'évolution des paramètres actimétriques à sept ans d'écart, nous avons observé que la qualité du sommeil de personnes de plus de 70 ans reste stable alors que la qualité de leur cycle veille-sommeil se dégrade. De plus, nous avons observé que cette dégradation était liée à de plus petits volumes de l'hippocampe antérieur, structure particulièrement vulnérable dans le vieillissement (Jouvencel et al., en préparation). Par ailleurs, nous n'avons pas observé de lien entre la dégradation du cycle veille-sommeil et la connectivité structurelle et fonctionnelle de cette structure. Ainsi, la qualité du sommeil et du cycle veille-sommeil évolue de manière différentielle chez la personne âgée et ont des conséquences différentes sur la santé cérébrale au cours du vieillissement<br>The main objective of this thesis was to determine how disturbances in the sleep-wake cycle and sleep can constitute factors of brain vulnerability. We used a combination of ecological measurements of the sleep-wake cycle and multimodal imaging collected from cohorts of French and Dutch volunteers in order to comprehensively understand the relationship between the sleep-wake cycle and brain health.We first showed the complementarity of objective and subjective methods (actimetry and PSQI) to assess the quality and duration of sleep in a sample of 1440 participants from the Rotterdam Study. While on average, subjective sleep quality was good (3.5 ± 3.3), objective sleep quality and quantity were poor with a sleep efficiency of 76.0% ± 8.3 and a duration of 6:13 ± 0:54. By studying the links between sleep quality and self-reported frequency of dizziness, we were able to observe that poor subjective sleep quality was significantly linked to the prevalence of dizziness while no link was observed with objective measures of sleep (Hoepel, Jouvencel et al., 2023).Then we demonstrated that intra-individual variability in the objective quality of sleep at the start of the night was linked to a greater accumulation of amyloid beta proteins in the brain of elderly subjects without cognitive disorders (Jouvencel et al., 2023). These results could result from a lower clearance efficiency of the glymphatic system in these subjects with disturbed sleep.Finally, by evaluating the evolution of actimetric parameters seven years apart, we observed that the quality of sleep of people over 70 years old remains stable while the quality of their sleep-wake cycle deteriorates. Furthermore, we observed that this degradation was linked to smaller volumes of the anterior hippocampus, a structure that is particularly vulnerable in aging (Jouvencel et al., in preparation). We did not observe a link between the degradation of the sleep-wake cycle and the structural and functional connectivity of this structure.Thus, the quality of sleep and the sleep-wake cycle evolve differentially in the elderly and have different consequences on brain health during aging
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Sawyer, Tiffoney L. "The effects of reversing sleep-Wake cycles on mood states, sleep, and fatigue on the crew of the USS John C. Stennis /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FSawyer.pdf.
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Thesis (M.S. in Applied Science (Operations Research))--Naval Postgraduate School, June 2004.<br>Thesis advisor(s): Nita Lewis Miller. Includes bibliographical references (p. 103-107). Also available online.
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Colby-Milley, Jessica. "Characterization of the sleep-wake cycle in the TgCRND8 mouse model of Alzheimer's disease: from early to advanced pathological stages." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121302.
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Individuals affected by Alzheimer's disease (AD) experience a progressive decline in cognitive function eventually leading to a debilitating loss of memory, reasoning and communication. Although AD is readily associated with such cognitive symptoms, patients can also experience behavioural and psychological symptoms, including perturbations of the sleep-wake cycle. Features of sleep-wake cycle disturbances in AD patients include increased nocturnal awakenings and a decrease in slow-wave non-rapid eye movement sleep (NREMS) and rapid eye movement sleep (REMS). Furthermore, changes in sleep quality can also be detected, as measured by the electroencephalogram (EEG) power spectrum. To determine if the TgCRND8 mouse model of AD mimics sleep alterations observed in AD patients, TgCRND8 mice were studied at 3, 7 and 11 months of age, representing differing pathological stages as defined by amyloid plaque load and distribution, as well as by the appearance of neuritic pathology, present from 5 months of age. Polysomnographic recordings were performed and the vigilance state durations over the light and dark cycles of 3, 7, and 11-month-old TgCRND8 were measured. During the active (dark cycle) and resting (light cycle) phases, at all ages studied, TgCRND8 mice spent a significantly greater amount of time awake and a significantly lower amount of time in NREMS when compared to non-transgenic (NTG) mice. Time spent in REMS was decreased during the active phase at 3 and 7 months of age in TgCRND8, while total time spent in REMS during the resting phase was not significantly affected in TgCRND8 at 3, 7 or 11 months. Following total sleep deprivation, 3-month-old TgCRND8 showed an effective recovery response, suggesting that alterations of the homeostatic regulation of the sleep-wake cycle may not contribute to sleep deficits observed at this age. The observed profile of sleep-wake cycle alterations supports the use of TgCRND8 mice as a model to study certain features of sleep-wake cycle disturbances associated with AD, such as increased wakefulness and decreased NREMS during the resting phase. Spectral power analysis of dark phase vigilance states revealed an increase in slow gamma power (20-50 Hz) during wakefulness at all ages studied and a decrease in slow-wave power <1 Hz during NREMS at 3 and 11 months of age. Brain rhythms during REMS were not altered at 3 months of age, however 7 and 11-month-old TgCRND8 displayed a decrease in alpha power (9-14 Hz) and an increase in slow gamma power (20-50 Hz) was also detected at 7 months. The observed tendency towards an increase in the spectral power of fast rhythms (slow gamma) is consistent with the pronounced increase in wakefulness observed in TgCRND8 and may reflect early changes in neuronal activity at the network level associated with amyloid pathology in the absence of severe neurodegeneration. Given the role of noradrenergic transmission within the ascending arousal system (AAS) in the regulation of vigilance states and promotion of arousal and the evidence for compensatory increases in noradrenergic signaling in AD, prazosin, an alpha-1-adrenoreceptor antagonist was administered to 3.5-month-old NTG and TgCRND8 mice to determine if this could restore normal NREMS levels in TgCRND8 mice. At a lower dose (2 mg/kg) prazosin increased NREMS in NTG mice but not in TgCRND8. However at a higher dose (5 mg/kg) an increase in NREMS was observed in both genotypes. Given that a different response to alpha-1-adrenoreceptor blockade was observed at a lower dose between the two genotypes, it may be possible that alterations in the noradrenergic regulation of the sleep-wake cycle are present in 3.5-month-old TgCRND8 and may explain why a higher dose (5mg/kg) of prazosin is required to achieve an increase in NREMS in TgCRND8.<br>Les individus atteints par la maladie d'Alzheimer (MA) démontrent une diminution des fonctions cognitives conduisant à une perte de la mémoire, le raisonnement, et la communication. Bien que la MA est associés à ses symptômes cognitifs, les patients peuvent aussi démontrer des symptômes non-cognitifs, tels que les troubles du sommeil. Les troubles du sommeil chez les patients atteintes de la MA incluent des éveils nocturne plus nombreux, et plus longues en duré que chez les sujets âgés sains, ainsi qu'une diminution du sommeil lent profonde, et dans les stades avancés, une diminution du sommeil paradoxal. Des changements dans la qualité du sommeil sont aussi présent, et peuvent être détecté par l'analyse des puissances spectrale des rythmes associés aux différents stades de sommeil. Pour déterminer si le modèle de la MA, la souris TgCRND8, reproduit les troubles de sommeil que l'on voit chez les patients, nous avons étudié la souris TgCRND8 a 3, 7 et 11 mois, des âges qui représentent des différentes stades pathologiques, définit par la quantité et la distribution de plaques amyloïdes ainsi que la pathologie neuritique, présent à partir de 5 mois. Durant la phase nocturne et la phase diurne, à tous les âges étudié, les souris TgCRND8 démontre une augmentation du temps passé éveillé et une diminution du sommeil lent en comparaison avec les souris non-transgénique (NTG). Une diminution du sommeil paradoxal a été observé à 3 et a 7 mois durant la phase nocturne, par contre, cet effet n'était pas présent durant la phase diurne à 3, 7 ou 11 mois. Après une dépravation total du sommeil, les souris TgCRND8 âges de 3 mois ont démontré une récupération homéostatique effective, suggèrent qu'une altération des mécanismes homéostatiques qui gèrent le sommeil ne contribue pas aux troubles de sommeil observé chez ses souris, à cette âge. L'analyse quantitative de l'électroencéphalogramme (EEG) a révèle une augmentation de la puissance spectrale dans la bande de fréquence gamma lent (20-50 Hz) durant l'éveil a 3, 7 et 11 mois et une diminution de la puissance spectrale des fréquences <1 Hz durant le sommeil lent a 3 et 11 mois. Durant le sommeil paradoxal, une diminution de la puissance spectrale dans la bande de fréquence alpha (9-14 Hz) a été observé à 7 et 11 mois et une augmentation dans la bande de fréquence gamma lent (20-50 Hz) à 7 mois. La tendance d'une augmentation de la puissance spectrale dans les bandes de fréquences rapide (gamma) est en accords avec l'augmentation prononcé du temps passe éveillé que l'on observe chez les TgCRND8 et pourraient être relié à des changements d'activité neuronale associé à l'accumulation de pathologie amyloïdes en absences de neurodégénérescence chez les souris TgCRND8. Étant donné le rôle de la transmission noradrénergiques dans la promotion de l'éveil, ainsi que les études démontrant la possibilités d'augmentation compensatoire d'activité noradrénergiques chez les patients atteints de la MA, les effets de prazosin, un antagonistes de récepteurs alpha-1-adrenergiques, ont été testé chez des souris NTG et TgCRND8 âges de 3.5 mois pour déterminé ci cela pourrait rétablir le sommeil lent chez les souris TgCRND8. A une dose de 2mg/kg, prazosin a augmenté la quantité total de sommeil lent chez les souris NTG mais pas les souris TgCRND8. A une dose plus élevé de 5 mg/kg, une augmentation de la quantité total du sommeil lent a été observé chez the souris NTG et aussi chez les souris TgCRND8. Etant donné que les souris TgCRND8 démontre une réaction différente à la dose faible de prazosin (2 mg/kg) en comparaison aux souris NTG, il est possible qu'il existe une altération dans le contrôle noradrénergique du sommeil chez les souris TgCRND8, est pourrait expliqué exigence d'une dose plus élevé (5 mg/kg) pour atteindre une augmentation du sommeil lent.
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Schenberg, Eduardo Ekman. "Caracterização eletrofisiológica da circuitaria hipocampal durante o ciclo sono-vigília do rato." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/47/47135/tde-08092010-144121/.
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Estrutura central do hipocampo, o corno de Ammon pode ser subdividido em pelo menos três áreas: CA1, CA2 e CA3. Enquanto CA1 e CA3 foram extensamente estudados, dado o envolvimento do hipocampo em processos cognitivos como a memória e patológicos como a epilepsia, CA2 tem sido largamente ignorado na literatura. Entretanto, este campo possui características específicas, tanto neuroanatômicas como bioquímicas e fisiológicas, sendo resistente à indução de plasticidade e recebendo aferência específica do núcleo supramamilar do hipotálamo, envolvido na circuitaria geradora/mantenedora do ritmo teta, oscilações centrais ao funcionamento do hipocampo. O objetivo deste estudo foi, portanto, caracterizar no animal em livre movimentação os padrões de atividade eletrofisiológica nas três áreas do corno de Ammon bilateralmente. Os resultados demonstraram que CA2 possui, em média, intervalos entre disparos mais prolongados que CA1 e CA3 durante o sono de ondas lentas e o sono REM. Nestas fases do ciclo a coerência entre CA1-CA2 foi mais elevada que entre CA1-CA3 e CA2-CA3 nos três ratos avaliados, em três faixas de freqüência: teta (6 a 12 Hz), gama lento (30 a 50 Hz) e gama rápido (90 a 110 Hz) ipsilateralmente. A coerência entre campos contralaterais é predominante no teta, sendo quase zero nas demais freqüências. Estes resultados corroboram trabalhos recentes que apontam CA2 como área distinta e sugerem que esta pequena região do corno de Ammon possa exercer papéis importantes na modulação da atividade das demais estruturas hipocampais e parahipocampais em processos de memória e em patologias como a epilepsia<br>The Ammons horn, central structure of the hippocampus, can be subdivided in at least three regions: CA1, CA2 and CA3. While CA1 and CA3 have been extensively studied given the hippocampus involvement in cognitive processes such as memory and pathological ones such as epilepsy, CA2 remains largely ignored. However, this sector contains specific neuroanatomical, biochemical e physiological characteristics, being resistant to induction of plasticity and receiving a specific afference from the supramammillary nucleus in the hypothalamus, involved in the generation/maintenance of the theta rhythm, central oscillations to hippocampal functioning. Therefore, the objective of this study was to characterize electrophysiological patterns of interaction in the three areas of the Ammons horn bilaterally. Results revealed that CA2 has a mean interspike interval larger than CA1 and CA3 during slow wave and REM sleep. During these stages of the sleep-wake cycle, coherence between CA1-CA2 was higher than CA1-CA3 and CA2-CA3 in the three animals evaluated, in three frequency bands: theta (6 to 12 Hz), slow gamma (30 to 50 Hz) and fast gamma (90 to 110 Hz) ipsilaterally. Coherence between contralateral fields was predominant in the theta band and almost zero in other frequencies. These results add to some previous published data showing that CA2 is distinct from the other subfields and that this small region of the Ammons horn may exert important roles in modulating activity in the other hippocampal fields and parahippocampal regions during memory and pathologies such as epilepsy
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Guzzo, Lia Alves Simões Matuzaki [UNIFESP]. "Caracterização do padrão do ciclo vigília-sono, avaliado pela actimetria, em uma amostra da população da cidade de São Paulo." Universidade Federal de São Paulo (UNIFESP), 2010. http://repositorio.unifesp.br/handle/11600/9175.
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Publico-313b.pdf: 2020262 bytes, checksum: 21e17092d7d10265944668be473ae2e0 (MD5)<br>Há poucos estudos que caracterizam o padrão do ciclo vigília-sono (CVS) na população geral, particularmente de grandes metrópoles. Nesse contexto, os objetivos do presente estudo foram avaliar: o CVS em uma amostra da população de São Paulo; as características do CVS de acordo com o cronotipo; e a concordância entre uma noite de polissonografia (PSG) com a actimetria, registradas simultaneamente. Métodos: Voluntários de um estudo com base populacional (São Paulo Epidemiologic Sleep Study), estratificado por sexo, idade (20-80 anos) e classe sócio-econômica, utilizaram actímetro (Actwach-64®) e preencheram diários de sono por um período mínimo de três dias consecutivos. Dados sócio-demográficos, de saúde e de sono foram coletados a partir de questionários e uma PSG completa foi realizada. Resultados: De uma amostra de 1101 voluntários selecionados para representar a população adulta da cidade de São Paulo, 359 utilizaram adequadamente o actímetro, dos quais 60% eram mulheres. A idade média foi 43 ± 14 anos e a duração média de sono observada foi de 365 ± 57 min. A maioria dos participantes apresentou padrão monofásico de sono (92%), 25 (7%) bifásico e 3 (1%) polifásico. Pela análise de cluster, os indivíduos foram agrupados em três grupos: matutino (61%), apresentou horário de inicio de sono em torno de 22:00h e tempo total de sono (TTS) médio de 374 ± 52 minutos; vespertino (32%), apresentou horário de início de sono em torno de 2:00h e TTS = 349 ± 66 minutos; e o terceiro grupo (7%) apresentou um padrão variável para o início do sono e TTS = 362 ± 58 minutos. Houve moderada correlação entre a PSG e a actimetria para o TTS (r=0,67) (p<0,001) e fraca correlação para a eficiência do sono (r=0,41) (p<0,001), latência do sono (r=0,2) (p<0,001) e vigília após o início do sono (r=0,26) (p<0,001). Conclusão: Esses resultados sugerem que a população avaliada apresentou predominantemente padrão monofásico de sono. Baseada na escolha das variáveis: horário de dormir, TTS, eficiência do sono e latência de sono, a actimetria foi eficaz em identificar perfil da população de acordo com o cronotipo. Embora tenham sido observadas diferenças entre a actimetria e a polissonografia, os resultados evidenciaram a adequação da actimetria para estudos do CVS.<br>Introduction: There are few studies evaluating the characteristics of the sleep-wake cycle (SWC) patterns in the general population. The aims of this study was to evaluate the SWC in a sample of the São Paulo city population; to assess the characteristics of SWC according to the chronotype; and to compare the polysomnography (PSG) and actimetry simultaneously recorded. Methods: Volunteers were selected from a population based study (São Paulo Epidemiologic Sleep Study), stratified by gender, age (20-80 years-old) and socioeconomic status. SWC was measured for at least three consecutive days using actimetry (Actwach-64®) and sleep diary. Social-demographic, health and sleep habits and complaints data were gathered from the questionnaires and a full-night PSG was performed. Results: Out of a sample of 1101 volunteers selected to represent the adult population of São Paulo, 359 volunteers wore the actimetry properly and 60% were women. The mean age was 43 ± 14 years and the mean total sleep time (TST) was 365 ± 57 minutes. The most of the participants presented monophasic pattern of sleep (92%), 7% had biphasic pattern and 1% had poliphasic pattern. According to a Two-step Cluster analysis, volunteers were included into three groups: morningness (61%), composed of individuals that had the sleep onset around 10:00 PM and TST was 374 ± 52 minutes; eveningness (32%), composed of individuals that had the sleep onset at 2:00 AM and TST was 349 ± 66 minutes; and the other group (7%), who had no defined sleep onset time and TST was 362 ± 58 minutes. We observed a moderate correlation between PSG and actimetry for TST (r=0.7) (p<0.001), and a weak correlation for sleep efficiency (r=0.4) (p<0.001), sleep latency (r=0.2) (p<0,001) and wake after sleep onset (r=0.3) (p<0.001). Conclusions: Our data suggest that the evaluated population presented mostly monophasic sleep pattern. Based on the selection of the variables (sleep onset time, TST, sleep efficiency and sleep latency) the actimetry was reliable to establish the profile of the population according to chronotype. Although differences between the actimetry and the PSG have been observed, the results support the use of actimetry to evaluate the sleep episodes.<br>TEDE
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Tang, Ni. "Circadian and non-visual regulation of light on sleep-wake states in humans and nocturnal rodents." Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10356.
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La lumière influence de nombreuses fonctions comportementales et physiologiques, comme les cycles veille-sommeil, la sécrétion de mélatonine, le réflexe pupillaire et le métabolisme du glucose. En tant que facteur environnemental clé, elle synchronise le système circadien sur un cycle de 24 heures. Les signaux lumineux sont perçus par les cellules ganglionnaires rétiniennes intrinsèquement photosensibles (ipRGCs), distinctes des bâtonnets et cônes responsables de la vision. Ces ipRGCs envoient les informations lumineuses au noyau suprachiasmatique (NSC) de l'hypothalamus, l'horloge circadienne principale du cerveau. Le NSC projette vers diverses structures cérébrales pour coordonner les processus rythmiques. Cependant, les ipRGCs influencent aussi directement des fonctions non visuelles, comme le sommeil et le métabolisme, en contournant la régulation circadienne. Cette double voie, circadienne et non circadienne, régule les effets non visuels de la lumière. Toutefois, les mécanismes précis par lesquels la lumière affecte les états veille-sommeil restent encore méconnus, de même que les structures cérébrales et les neurotransmetteurs impliqués. La lumière artificielle, omniprésente dans la vie moderne, notamment la nuit, perturbe les cycles naturels jour/nuit, ce qui suscite des inquiétudes.Notre projet vise à comprendre les effets de la lumière sur la veille et le sommeil en utilisant des modèles animaux et des études humaines. Dans nos expériences sur des souris génétiquement modifiées, nous avons étudié si l'orexine et l'histamine jouent un rôle dans les effets inducteurs du sommeil de la lumière. Les souris ont été exposées à différents cycles lumineux (LD12:12, DD et LD1:1). Nous avons observé que la lumière augmentait le sommeil à ondes lentes (SWS) durant la phase sombre chez les souris sauvages (WT), mais cet effet était atténué chez les souris knock-out OX, HDC et OX/HDC. La lumière augmentait également l'activité delta de l'EEG pendant le SWS chez les souris WT, OX knock-out et OX/HDC knock-out, mais pas chez les souris HDC knock-out. De plus, la lumière induisait un sommeil rapide et durable chez les souris WT, alors que cet effet était plus lent et de plus courte durée chez les modèles knock-out, suggérant que la transmission de l'orexine et de l'histamine est nécessaire pour les effets inducteurs de la lumière. Dans l'étude humaine, 20 hommes en bonne santé ont été exposés à quatre intensités lumineuses (0, 3, 8 et 20 lux) pendant 5 jours dans un environnement contrôlé. Nous avons constaté que le réveil après l'endormissement (WASO) était plus long sous 20 lux comparé aux intensités lumineuses plus faibles, et que l'efficacité du sommeil était réduite sous 20 lux. Les niveaux de mélatonine et de cortisol au réveil n'ont pas varié entre les conditions lumineuses. En revanche, la fréquence cardiaque (HR) a diminué et la variabilité de la fréquence cardiaque (HRV) a augmenté sous 20 et 3 lux par rapport à 0 lux. Le taux de glucose durant le sommeil était plus élevé sous faible lumière (3 et 20 lux) que sous 0 lux. De plus, l'exposition nocturne à la lumière a altéré la sensibilité à la lumière et la performance cognitive le lendemain. Nous concluons que même une faible intensité de lumière artificielle nocturne (ALAN) peut perturber le sommeil et affecter les fonctions physiologiques<br>Light influences a wide range of behavioral and physiological functions, including sleep-wake cycles, melatonin secretion, pupil light reflex, glucose metabolism, and more. As a key environmental factor, light synchronizes the circadian system with a roughly 24-hour cycle. Light signals are detected by a specific type of retinal cell, intrinsically photosensitive retinal ganglion cells (ipRGCs), which are distinct from the classical photoreceptors—rods and cones—that are primarily involved in vision. These ipRGCs transmit light information to the brain's master circadian clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN then projects to various brain structures, coordinating rhythmic behavioral and physiological processes. Notably, ipRGCs also send projections to brain regions beyond the SCN, bypassing circadian regulation to directly influence non-visual functions like sleep, wakefulness, and metabolism. This dual pathway—circadian and non-circadian—mediates light's non-visual effects on the body. However, the exact mechanisms by which light affects sleep-wake states, and which brain structures and neurotransmitters are involved, remain largely unknown. As artificial light becomes increasingly common in modern life, including during nighttime, its disruption of natural light-dark cycles raises concerns. The aim of our project is to explore the wake-promoting and sleep-inhibiting effects of light using both animal models and human studies. In the animal studies, we employed genetically modified mouse models with disrupted histamine and/or orexin transmission to investigate whether these neurotransmitters mediate the sleep-inducing effects of light. Mice were exposed to three conditions: LD12:12, DD, and LD1:1 cycles. Our findings revealed that light significantly increased slow-wave sleep (SWS) during the dark phase in wild-type (WT) mice, but this effect was diminished in OX knockout, HDC knockout, and dual OX/HDC knockout mice. Additionally, light induced a significant increase in EEG delta activity during SWS in WT, OX knockout, and OX/HDC knockout mice, but not in HDC knockout mice. Furthermore, while light induced sleep rapidly and for a sustained duration in WT mice, this effect was slower and shorter-lasting in the knockout models. These results suggest that the sleep-inducing effects of light require both orexin and histamine transmission. In the human study, 20 healthy male participants were exposed to four different light conditions (0, 3, 8, and 20 lux) during a 5-day protocol in a controlled laboratory setting. We found that wake after sleep onset (WASO) was significantly higher under 20 lux compared to lower light intensities, and sleep efficiency was lower under 20 lux than under 3 and 8 lux. Interestingly, there were no significant differences in salivary melatonin and cortisol levels at wake time between the four light conditions. Similarly, body temperature during sleep remained unchanged across light conditions, but heart rate (HR) and heart rate variability (HRV) were affected, with a decrease in HR and an increase in HRV under 20 lux and 3 lux compared to 0 lux. Glucose levels during sleep were significantly higher under low-light conditions (3 and 20 lux) than under 0 lux. Moreover, nocturnal light exposure impaired sensitivity to light and cognitive performance the following morning. Our study concludes that even very low-intensity artificial light at night (ALAN) can disturb sleep and affect physiological functions
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Melone, Marie-Anne. "Diagnοstic and therapeutic strategies οf circadian and sleep/wake rhythm disοrders in at-risk pοpulatiοns". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMR023.
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Les recommandations en matière de santé du sommeil préconisent 7 à 9 heures de sommeil par nuit pour la population générale. Pourtant, la dette chronique de sommeil persiste et présente des risques importants pour la santé, notamment en termes de maladies métaboliques, cardiovasculaires et neurocognitives. Cette dette chronique de sommeil est souvent attribuée au conflit entre le mode de vie moderne - l'éclairage artificiel et les obligations sociales - et nos rythmes circadiens endogènes, ce qui conduit à une perturbation appelée le désalignement circadien. Les rythmes circadiens sont les oscillations naturelles des processus physiologiques. Ces rythmes sont essentiels pour aligner nos processus physiologiques et comportementaux sur le temps solaire afin d'anticiper les changements dans notre environnement. Le désalignement circadien est de plus en plus souvent incriminé dans divers états pathologiques. Le diagnostic des troubles des rythmes circadiens ou rythmes veille/sommeil reste difficile en pratique, car sa définition repose en partie sur des évaluations subjectives de la qualité du sommeil. Les questionnaires et les agendas de sommeil bien qu’ils soient des outils validés établissent des mesures indirectes de notre chronotype et des rythmes veille/sommeil. Le gold standard pour l’évaluation de notre rythmicité circadienne est la mesure biologique de la sécrétion de la mélatonine. Ceci souligne la nécessité d'améliorer les méthodes de diagnostic afin de mieux identifier la prévalence de ces troubles et ainsi pouvoir proposer des mesures thérapeutiques adaptée. Ceci pourrait contribuer à prévenir le développement de pathologies en liens avec ce désalignement circadien. Dans ce contexte, notre travail s’intéresse à la prévalence, les facteurs de risque et les conséquences des désalignements circadiens, chez des populations particulièrement à risque comme les étudiants-sportifs et les patients de soins intensifs, où les donneurs de temps sont perturbés ; générant des conséquences en termes d’altération des performances et du pronostic. Ce travail comprend les résultats de trois études et une revue de littérature sur la prévalence des troubles des rythmes veille/sommeil, leurs facteurs de risque, les conséquences et les traitements potentiels dans les populations des étudiants-sportifs et des patients de soins intensifs<br>Sleep health guidelines advocate for 7 to 9 hours of nightly sleep for the general population, yet sleep debt persists, presenting significant health risks, including metabolic, cardiac, mental, and neurocognitive diseases. This widespread sleep debt is often attributed to the conflict between modern lifestyles—characterized by artificial lighting, shift work, and social obligations—and our innate circadian rhythms, leading to a condition known as circadian dysrhythmia. Circadian rhythms are the natural oscillations in physiological processes that are essential for aligning genetic, physiological, and behavioral patterns with solar time to anticipate changes in our environment. The misalignment of these rhythms is increasingly linked to various health disorders. Diagnosing circadian rhythms and sleep/wake disorders poses challenges, as part of its definition relies on subjective assessments and clinical evaluations of sleep quality. Moreover, sleep/wake timing or chronotype questionnaires, although validated, may not accurately reflect individual circadian clocks. While melatonin measurement is considered the gold standard, its practical implementation is difficult, making actigraphy and sleep logs more common tools for identifying circadian rhythms and sleep/wake disorders. This highlights the need for improved diagnostic methods. Potential therapeutic interventions could help improve circadian dysrhythmias related health outcomes. In this context, this manuscript delves into the prevalence, risk factors, and consequences of circadian rhythms and sleep/wake disorders, particularly focusing on at-risk populations like student-athletes and critically ill patients, where misaligned zeitgebers exacerbate health risks. This work includes three studies’ findings and one narrative review on circadian rhythm and sleep/wake disorders, their risk factors, consequences, and potential treatments in populations prioritizing performance (student-athletes) and recovery (critically ill patients)
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Teixeira, Liliane Reis. "Análise dos padrões do ciclo vigília-sono de adolescentes trabalhadores e não trabalhadores, alunos de escola pública no município de São Paulo." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-28112006-183701/.
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Com o início da puberdade ocorrem modificações nos componentes biológicos do ciclo vigília-sono. Estes estão associados a fatores sociais, como os horários escolares, lazer e trabalho e podem reduzir as horas disponíveis para o sono. Foi objetivo principal deste trabalho avaliar os padrões do ciclo vigília-sono de estudantes trabalhadores e não trabalhadores, alunos de escola pública do município de São Paulo. Vinte e sete adolescentes entre 14-18 anos de idade responderam ao questionário de caracterização das condições de vida, saúde e trabalho, e simultaneamente, utilizaram actígrafos; preencheram o protocolo diário de atividades e o diário de sono por 15 dias consecutivos. As variáveis analisadas durante a semana e nos fins-de-semana foram: horário de início e término do sono noturno, número e duração dos despertares noturnos, duração do sono noturno, latência subjetiva e eficiência do sono noturno, facilidade em adormecer à noite e despertar pela manhã, qualidade subjetiva do sono noturno, número de cochilos, horário de início e término do cochilo, duração do sono diurno e duração do sono diário. As variáveis foram testadas através da análise de variância (ANOVA) de 1 fator e teste t-Student para a comparação de 2 médias. Foram feitas múltiplas comparações utilizando a correção de Tukey-HSD. Os resultados significantes foram: efeito do trabalho nos fins-de-semana para o horário de dormir [F(1,23)=6,1; p=0,02] e durante a semana para o horário de acordar [F(1,23) = 17,3; p=0,00]. Para o grupo dos trabalhadores, o horário de acordar foi semelhante ao longo da semana e 1h21min mais tardio nos fins-de-semana [t=-3,27;p<0,01]. Na duração do sono verificamos efeito do trabalho durante a semana [F(1,23)=16,7; p=0,00], efeito do sexo [F(1,23)=10,8; p=0,00] e a interação entre o trabalho e sexo nos fins-de-semana [F(1,23)=4,8; p=0,04]. Os adolescentes trabalhadores possuem uma duração do sono noturno em média 1h30min a menos durante a semana quando comparado com o fim-de-semana [t=-4,04;p<0,01]. Para a duração do sono diurno verificamos a interação entre trabalho e sexo durante a semana [F(1,23)=5,6; p=0,03], e para a duração total de sono verificamos efeito do trabalho durante a semana [F(1,23)=14,3; p=0,00] e efeito do sexo nos fins-de-semana [F(1,23)=10,1; p=0,00]. Os adolescentes trabalhadores possuem uma duração total do sono em média 1h20min a menos durante a semana quando comparado com o fim-de-semana [t=-3,32;p<0,01]. Para as queixas relacionadas ao sono noturno encontramos efeito do trabalho para a facilidade em despertar pela manhã [F(1,23)=6,5; p=0,02] e para a qualidade subjetiva do sono noturno durante a semana [F(1,23)=6,2; p=0,02]. Concluímos que o ciclo vigília-sono dos adolescentes trabalhadores é caracterizado por: acordar mais cedo e ter menor duração do sono noturno e do sono total durante a semana do que os não-trabalhadores. Nos fins-de-semana os trabalhadores dormem mais cedo, mas permanecem com uma duração de sono menor que os colegas não trabalhadores. Em relação ao sexo, verificou-se que os adolescentes do sexo masculino possuem uma menor duração de sono noturno e do sono total nos fins-de-semana. Os adolescentes do sexo feminino possuem uma maior duração do cochilo durante a semana. Os adolescentes trabalhadores relataram maior dificuldade para acordar e percebem seu sono como de pior qualidade durante a semana. O trabalho destes adolescentes tem repercussões negativas na duração e percepção da qualidade do sono, com possível privação crônica de sono. O efeito do trabalho afeta de forma significativa a qualidade de vida atual podendo limitar as perspectivas dos adolescentes quanto ao seu desenvolvimento intelectual, bem estar físico e mental.<br>Changes of the sleep-wake cycle are associated to several factors, such as, puberty, school hours, duration and type of activities during free time, working hours. The objective of this study was to evaluate patterns of sleep-wake cycles among high school students who work and dont work. Twenty-seven high school students, ages 14-18 years old participated in the study. They were studying in a public school of São Paulo, Brazil. Their Monday-Friday study hours were 19:00 to 22:30h. They answered a comprehensive questionnaire about working and living conditions, and reported health symptoms and diseases. Also, activity- rest measurements were continuously recorded with Actigraph (Ambulatory Monitoring, USA). Activities and sleep dairies during 15 consecutive days were also reported. Main variables were tested using one factor ANOVA and t-Student tests were performed to compare sleep duration during Monday-Friday and weekends. It was used Tukey HSD test for multiple comparisons among the variables. Results of sleep showed working students went to sleep earlier during weekends [F(1,23)= 6.1; p= .02] and woke up earlier during working days than non-working students [F(1,23)=17,3; p= .00].The duration of night sleep is shorter among working students [F(1,23)= 16,7; p= .00], and males [F(1,23)=10,8; p= .00] than non-working students. The male working students showed a shorter nap duration during the working week [F(1,23)= 5,6; p= .03] compared to females and non-working students. Reported sleep complaints were difficulties waking up in the morning [F(1,23)= 6,2; p= .02]. Conclusions: work caused negative consequences to sleep among adolescents, with possible build up of a chronic sleep debt. This can affect the quality of life, and schooling development of working students.
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Silva, Francisca Patricia da. "Avalia??o do padr?o do ciclo sono-vig?lia e a cogni??o em estudantes de medicina com diferentes esquemas de hor?rios de aulas." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17307.
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Previous issue date: 2010-10-07<br>The sleep patterns of students entering the university, is accompanied by many factors that can lead to changes in sleep habits, such as academic demands, new social opportunities, reduced parental care and irregular teaching schedules. The irregular pattern of sleep-wake cycle is usually accompanied by several daytime consequences, for example, reduced levels of motivation, performance, concentration, alertness and mood as well as increased fatigue and sleepiness.Thus, there are numerous reasons to support the fact that these students may suffer damage in their academic performance. The aim of this study was to evaluate the sleep-wake cycle (SWC) and cognition in medical students with different schemes teaching schedules. One group started classes at 08am, while the other started at 07am. We analyzed the data from 88 volunteers, 39 from each group. However, only those who participated in both stages of the study (n = 78) underwent cognitive testing. For subjective evaluation of the SWC was used questionnaires to check the quality of sleep, chronotype, daytime sleepiness and sleep habits. For objective evaluation was used actigraphy. For cognitive assessment was used the test MoCA (Montreal Cognitive Assessment). The results indicate that the group has class earlier had a greater irregularity of the SWC and a worse performance in cognitive testing. There was a difference between the schedules the week and weekend in the subjective variables, bedtime, wake up and sleep duration in both groups. The objective variables, time in bed showed difference between the schedules the week and weekend to the group started class at 08am and the variables bedtime, get up time, actual sleep time, time in bed and wake bouts in the class at 07am. In the cognitive test, there were differences between the groups in overall score and in the areas of executive function and memory recall. Thus, it is suggested that the class starting time may cause irregularity of the SWC and the irregularity may cause mild cognitive impairment. Moreover, cognitive testing MoCA was sensitive to detect differences among students, although the difference between the schedules is small<br>O padr?o de sono dos estudantes ao entrarem na universidade, ? acompanhado por muitos fatores que podem levar a mudan?as nos h?bitos de sono, tais como demanda acad?mica, novas oportunidades sociais, diminui??o do cuidado dos pais e hor?rios de aulas irregulares. O padr?o irregular de sono-vig?lia ? usualmente acompanhado por v?rias consequ?ncias diurnas, como diminui??o nos n?veis de motiva??o, desempenho, concentra??o, aten??o e humor, bem como aumento da fatiga e da sonol?ncia. Assim, existem in?meras raz?es para apoiar o fato de que, esses estudantes universit?rios, podem sofrer preju?zos em seu desempenho acad?mico. O objetivo desse estudo foi avaliar o padr?o ciclo sono-vig?lia (CSV) e a cogni??o em estudantes de medicina com diferentes esquemas de hor?rios de aulas. Uma turma iniciava as aulas ?s 08 horas da manh?, enquanto a outra iniciava ?s 07 horas. Para isso contamos com 88 volunt?rios. Por?m, desses, apenas os que participaram das duas etapas no estudo (n=78) realizaram o teste cognitivo. Para a avalia??o subjetiva do CSV foi utilizado question?rios para verificar a (1) qualidade de sono, (2) cronotipo, (3) sonol?ncia diurna e (4) h?bitos de sono. Para avalia??o objetiva foi utilizado o act?metro e para avalia??o cognitiva o teste MoCA (Montreal Cognitive Assessment). Os resultados indicam que a turma que tem aula mais cedo teve uma maior irregularidade do CSV e um pior desempenho no teste cognitivo. Houve diferen?a entre os hor?rios da semana e do fim de semana nas vari?veis subjetivas, hora de deitar, hora de levantar e dura??o do sono, em ambas as turmas. E nas vari?veis objetivas, tempo na cama na turma das 08h e, hora de dormir, hora de acordar, tempo real de sono, tempo na cama e despertares noturnos na turma das 07h. No teste cognitivo, houve diferen?a entre as turmas no escore geral e nos dom?nios de fun??o executiva e evoca??o de mem?ria. Assim, sugere-se que o hor?rio de in?cio das aulas pode provocar irregularidade do CSV e, essa irregularidade pode provocar um d?ficit cognitivo leve. Al?m disso, o teste cognitivo MoCA foi sens?vel para detectar diferen?as entre os estudantes, apesar da diferen?a entre os hor?rios ser pequena
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Teixeira, Liliane Reis. "Efeitos das atividades diárias nos níveis de sonolência, em estudantes do Ensino Médio, trabalhadores e não-trabalhadores." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-03042007-175137/.
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Introdução - A sonolência é descrita como a interação entre o momento circadiano para adormecer e o aumento da necessidade de sono, e está em geral, associada ao decréscimo do alerta, do tempo de reação, da memória, da coordenação psicomotora, do entendimento da informação, do tempo para se tomar decisões, da maior incidência de uso de substâncias estimulantes e de substâncias álcoolicas. Na adolescência, a sonolência limita as perspectivas dos adolescentes quanto ao seu desenvolvimento intelectual. Muito pouco se conhece sobre a percepção da sonolência em estudantes trabalhadores. Objetivo - Verificar variações da sonolência ao longo do dia e o possível impacto das atividades diárias e estilos de vida na sonolência em estudantes. Metodologia - A população estudada compreendem estudantes trabalhadores e não-trabalhadores, alunos do ensino médio do período noturno de uma escola pública estadual da cidade de São Paulo, SP. Participaram estudantes entre 14 e 21 anos de idade incompletos. Os estudantes selecionados preencheram os questionários de: caracterização das condições de vida, saúde e sono, matutinidade-vespertinidade, caracterização das condições de trabalho e freqüência alimentar. Em seguida foi realizada a obtenção de registros sobre o ciclo vigília-sono dos estudantes através de métodos subjetivos (Protocolo diário de atividades, diário de sono e escala de sonolência) e objetivos (Actimetria). As variáveis sócio-demográficas, estilos de vida, condições de trabalho e do ciclo vigília-sono foram testadas através do teste t-Student, ANOVA para três fatores (dia da semana, horário e trabalho), Qui-Quadrado de Pearson (c2) e análise de regressão. Resultados - 1) a duração média do sono nos dias da semana para os estudantes trabalhadores foi em torno de 7h, enquanto a duração do sono dos estudantes não trabalhadores foi em torno de 9h; 2) os padrões de sonolência de estudantes trabalhadores são diferentes dos estudantes não-trabalhadores. Verificamos que os estudantes trabalhadores são mais sonolentos que os estudantes não-trabalhadores no primeiro registro diário (07├ 09 h) e no último (22├ 24 h). Verificamos que os estudantes trabalhadores são mais sonolentos que estudantes não-trabalhadores na segunda-feira após o almoço (13├ 15 h), na quarta-feira durante as aulas (19├ 21 h) e na sexta-feira antes de dormir (22├ 24 h). Aos domingos, entre 22├ 24 h foi encontrada o maior nível de sonolência entre os estudantes trabalhadores. Também, neste momento, os trabalhadores são mais sonolentos que os estudantes não-trabalhadores em todos os outros dias e horários; 3) os fatores independentemente associados a estar sonolento foram: trabalhar, ser do sexo feminino, consumir álcool, ter maior dificuldade para adormecer e ir dormir após as 24h. Conclusões - Os padrões de sonolência de estudantes trabalhadores são diferentes dos estudantes não-trabalhadores e as variáveis do ciclo vigília-sono interferem nos níveis de sonolência ao longo do dia. Além dos fatores cronobiológicos outros fatores estão relacionados às mudanças nos níveis da sonolência: a) fatores individuais; b) fatores sociais; c) fatores sócio-demográficos e d) estilos de vida. Essa gama de fatores acaba levando ao aumento da sonolência no início e fim do dia para os estudantes trabalhadores, podendo interferir no rendimento escolar e prejudicar o desenvolvimento físico e mental, característicos da adolescência. Programas de intervenção tais como, o conhecimento sobre a higiene do sono e as políticas de inserção social que permitam aos estudantes manter um padrão de vida adequado sem ter que sujeitar a longas jornadas de trabalho enquanto na adolescência, devem ser implementados.<br>Introduction Sleepiness is described as an interaction between the circadian phase and the increase in pressure to sleep. In general, it is associated with a decrease in alertness levels, reaction time, memory, psychomotor coordination, information assimilation, time to take decisions, and larger consumption of stimulant and alcoholic substances. In adolescence, sleepiness restricts the adolescents perspectives as to his/her intellectual development. Knowledge on perception of sleepiness in working students is poor. Objective Verifying patterns of sleepiness along the day and the possible impact of daily activities and life styles on sleepiness among working and non-working students. Methods The population studied comprised working and non-working high school students attending evening classes (19:00-22.30pm) at a public school in São Paulo, Brazil. The study group consisted of working and non-working students aged 14-21. The students selected filled in a questionnaire on living conditions, health and sleep, morningness-eveningness, characterization of working conditions, and frequency of food consumption. As a second step, records of their sleep-wake cycle were obtained through subjective methods (daily protocol of activities, sleep diary and sleepiness scale), as well as objective methods (Actigraphy). Socio-demographic, life style, work conditions and sleep-wake cycle variables were tested with the use of three-way ANOVA test (week day, time and work), Persons Qui-Square test (c2) and regression analysis. Results - 1) The average sleep duration for working students during weekdays was around 7 hours, whereas the sleep duration for non-working students was around 9 hours; 2) working students sleepiness patterns are different from those of non-working students. We found that working students were sleepier than non-working students in the first period (07:00am-09:00am) and in the last period recorded (10:00pm-12:00pm). We also found that working students were sleepier on specific days: on Mondays after lunch time (01:00pm-03:00pm), on Wednesdays during classes (07:00pm-09:00pm) and on Fridays before bedtime (10:00pm-12:00pm). The highest level of sleepiness among students was found on Sundays, between 10:00pm-12:00pm. Also, at this time period working students in general were sleepier than non-working students, independently of the period and time of the day. 3) Other factors associated with sleepiness were: work, being a female, alcohol consumption, easiness of sleeping and going to bed after midnight. Conclusions The sleepiness patterns for working students are different from those for non-working students, and the sleep-wake cycle variables interfere in sleepiness levels during the day. In addition to chronobiological factors, there are other factors associated with changes in sleepiness levels: a) individual factors; b) social factors; c) socio-demographic factors; and d) life style. All these factors contribute to increase in working students sleepiness at the beginning and end of the day; this may interfere in their school performance, impairing their physical and mental development, which is characteristic of adolescence. Intervention programs, such as those that provide information on sleep hygiene, and those related to social insertion, which would allow students to maintain and adequate life standard without having to be submitted to extended work journeys, should be implemented.
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Torres, Fernanda de Jesus. "Ciclo vigília/sono em adolescentes de uma população indígena." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/47/47135/tde-12062006-134852/.
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O ciclo vigília/sono (CVS) muda durante a adolescência. Nos dias letivos, há maior sonolência diurna e menor duração de sono do que nos finais de semana. Além disso, os adolescentes apresentam atraso da fase de sono. Acredita-se que essas mudanças resultam da interação entre fatores biológicos e ambientais. Neste trabalho, observamos o CVS de 21 jovens Guarani da Aldeia Boa Vista - SP, que vivem numa floresta, sem energia elétrica. Pretendíamos verificar se eles apresentam um padrão semelhante ao descrito em adolescentes urbanos ou se tal característica é menos evidente, como tem sido relatado na população rural. Aplicamos o Questionário de Hábitos de Sono e o Questionário de Matutinidade e Vespertinidade. Os participantes preencheram diários de sono, usaram actímetros e coletaram temperatura a cada 3 horas, na vigília, por 10 ou mais dias consecutivos em 3 ocasiões com intervalos de 6 meses. Fizemos inspecção visual dos actogramas de diários e actímetros, comparando-os entre si por meio de teste t de Student; avaliamos a significância das oscilações da temperatura pelo Método Cosinor; utilizamos as correlações de Pearson e Spearman para identificar relações entre variáveis, adotando como nível de significância α=0,05. Comparamos as etapas e discutimos os resultados no cenário de outras pesquisas realizadas com adolescentes. Observamos atraso da fase do sono e da temperatura oral nos Guarani, conforme descrito entre adolescentes de regiões urbanas, e menor duração do sono nos finais de semana do que nos demais dias. Os resultados apontam para a importância de fatores biológicos no atraso da fase dos ciclos vigília/sono e de temperatura na adolescência.<br>The sleep/wake cycle (SWC) changes along adolescence. During weekdays there is higher diurnal sleepiness and shorter sleep duration than on weekends; moreover, they display sleep phase delay. Some authors believe these changes result from the interaction between biological and environmental factors. In this work, we observed the SWC in 21 adolescents from the ethnic group Guarani living in Boa Vista village (São Paulo) who live in a rural area, without electric light. We intended to verify whether they show a SWC pattern similar to that found in urban adolescents or if these characteristics are less evident under their condition as has been reported for rural area adolescents. We applied Sleep Habits and Morningness-Eveningness questionnaires. The participants kept Sleep Diaries and wore wrist actimeters for at least 10 consecutives days, and collected oral temperature every 3 hours when awake. This protocol was applied on 3 occasions with 6 months intervals between them. We examined the actograms from Diaries and Actimetries, comparing them with t Student test; we evaluated the temperature oscillations by Cosinor Method, we used Pearsons and Spearmans correlations in order to identify relationships between the measures, adopting the significance level at α=0.05. We compared the occasions and considered our results in the context of adolescent sleep researches. We observed sleep and temperature phase delays in Guarani adolescents similar to the delays found in other groups, as well as shorter sleep duration on weekends than on weekdays. Our results point to the importance of biological factors on sleep/wake and temperature phase delays along adolescence.
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Serpe, Rossana. "Identification of clock neurons and downstream circuits that are involved in sleep control in Drosophila melanogaster." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS257.
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Le moment, la qualité et la quantité de sommeil dépendent de l'interaction fine entre l'horloge circadienne et la machinerie homéostatique (Borbely A. et al., 1982, Daan S. et al., 1984, Borbely et Achermann, 1999). Au cours des dernières années, l'utilisation de divers organismes modèles a fourni de nouvelles perspectives sur les mécanismes neuronaux et moléculaires de la régulation du sommeil (Miyazaki S. et al., 2017). Cependant, les bases moléculaires de l'homéostasie du sommeil et les circuits neuronaux sous-jacents à son interaction avec le réseau circadien n'ont pas été établis en détail.Dans ce travail de thèse, j'ai utilisé la mouche Drosophile melanogaster comme système modèle pour étudier la fonction d'un sous-ensemble de neurones d'horloge, les DN1ps, dans la mise en place du sommeil. Des études antérieures ont suggéré un rôle de ces neurones circadiens dans la régulation du sommeil (Kunst et al., 2014, Guo et al 2016, Lamaze et al., 2017, Guo et al., 2017). J’ai ainsi démontré que les cellules d'horloge DN1ps DH31 (+) CRY (+) sont impliquées dans la suppression du sommeil. Par ailleurs, j’ai mis en évidence un circuit en aval des DN1ps, qui comprend le groupe dopaminergique postérieur apparié latéral 1 (PPL1) et les neurones dorsaux en forme d’éventail (dFSB), un centre homéostatique récemment décrit pour la régulation du sommeil chez la drosophile (Donlea JM et al., 2011, Liu S. et al., 2012, Ueno et al., 2012, Donlea JM et al., 2014, Pimentel et al., 2016, Qian et al., 2017, Donlea JM. et al., 2018). Nos résultats indiquent que la suppression du sommeil nocturne nécessite la signalisation DH31-R2 dans une sous-population des neurones dopaminergiques PPL1, qui projette au dFSB. Fait intéressant, la perte de sommeil de jour et de nuit médiée par les DN1ps dépend de l'inhibition du dFSB. Néanmoins, nous suggérons que les neurones DN1ps CRY (-) favoriseraient le sommeil, en concordance avec d'autres travaux (Guo et al., 2016; Guo et al., 2017).Ces résultats fournissent de nouvelles données sur le lien entre l'horloge circadienne et l'homéostasie du sommeil, impliqué dans la régulation du comportement sommeil-éveil chez Drosophile melanogaster<br>The timing, quality and quantity of sleep depend on the fine interaction between circadian clock and homeostatic machinery (Borbely A. et al., 1982; Daan S. et al., 1984; Borbely and Achermann, 1999). In the recent years, the employment of various model organisms has provided new insights into the neuronal and molecular mechanisms of sleep regulation (Miyazaki S. et al., 2017). However, the molecular basis of the sleep homeostat and the neuronal circuitry underlying its interaction with the circadian network haven’t been established in details.In this work, I use the fruit fly Drosophila melanogaster as a model system to investigate the sleep function of a subset of clock neurons, the DN1ps. Previous studies have already suggested a sleep-regulating role for these circadian neurons (Kunst et al. 2014, Guo et al. 2016; Lamaze et al., 2017; Guo et al. 2017). Here, we report the DH31-positive CRY-positive DN1ps as sleep suppressing clock cells. Furthermore, we identify a sleep-relevant circuit downstream of the DN1ps which includes the paired posterior lateral 1 (PPL1) dopaminergic cluster and the dorsal Fan-shaped body projecting (dFSB) neurons, a recently described homeostatic center for sleep regulation in Drosophila (Donlea JM. et al., 2011; Liu S. et al., 2012; Ueno et al., 2012; Donlea JM. et al., 2014; Pimentel et al., 2016; Qian et al., 2017; Donlea JM. et al., 2018). Our results indicate that the night-time sleep suppression requires DH31-R2 signaling in the PPL1-to-dFSB dopaminergic neurons. Interestingly, both day and night-time DN1ps-mediated sleep loss rely on the inhibition of the dFSB. Nevertheless, we suggest the CRY-negative DN1ps as sleep promoting clock neurons, in concordance with other works (Guo et al. 2016; Guo et al. 2017).These findings provide a novel link between circadian clock and sleep homeostat, in the regulation of sleep-wake behavior in Drosophila melanogaster
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Barone, Mark Thomaz Ugliara. "Ciclo vigília/sono em portadores de diabetes mellitus tipo 1." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42137/tde-23012012-164619/.
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O objetivo do presente estudo foi avaliar possíveis relações entre o diabetes mellitus tipo 1 (DM1) e controle glicêmico, e o ciclo vigília/sono. Participaram 18 voluntários com DM1 (idade: 26,3±5,1), sem complicações, não obesos, sem alterações no sono; e 9 no grupo controle (idade: 28,8±5,3). Os dados foram coletados através de: diário de sono e de glicemia, actímetria (Tempatilumi), polissonografia, 6-sulfatoximelatonina, questionário de Epworth, e sensor de glicose durante a polissonografia nos DM1. A associação entre controle glicêmico e o ciclo vigília/sono foi evidenciada. A duração inadequada, a baixa qualidade, a fragmentação do sono e a secreção reduzida de melatonina, possivelmente, favoreceram um pior controle glicêmico em DM1. Por outro lado, indivíduos DM1, com melhor controle glicêmico, podem se beneficiar de maior secreção de melatonina noturna e menor fragmentação e latência do sono. O controle mais adequado, potencialmente, regulariza o ciclo vigília/sono e previne ou retarda o desenvolvimento de complicações crônicas.<br>The aim of the present study was to evaluate the association of type 1 diabetes mellitus (T1DM) and glycemic control with the sleep/wake cycle. Eighteen T1DM volunteers and 9 control subjects, non-obese, without chronic complications, and no sleep disorders participated. Data were collected with sleep and glycemia log, actigraphy (Tempatilumi), polysomnography, 6-sulphatoxymelatonin, Epworth questionnaire, and glucose sensor during the polysomnography night for T1DM. The association between glycemic control and sleep/wake cycle was observed. The inadequate duration, poor quality, and fragmented sleep besides the reduced melatonin secretion possibly favored a worse glycemic control in T1DM. On the other hand, we understand that T1DM individuals with better glycemic control may benefit from increased melatonin secretion and less sleep fragmentation and latency. Therefore, a better glycemic control potentially regulates the sleep/wake cycle and prevents or delays the development of chronic complications.
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Vasconcelos, Suleima Pedroza. "A organização temporal do trabalho e exposição à luz e suas repercussões no ciclo vigília-sono e secreção de melatonina de trabalhadores de uma reserva extrativista amazônica." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-09022015-084121/.
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Objetivo Investigar a associação dos horários de trabalho e padrões de exposição à luz com ciclo vigília-sono e secreção de melatonina em trabalhadores da Reserva Extrativista Chico Mendes. Método Estudo transversal realizado no município de Xapuri, Acre, com 340 seringueiros e 148 trabalhadores uma fábrica de preservativos (46 trabalhadores administrativos e 102 operários). Na primeira etapa do estudo foram coletados, por meio de questionários, dados sociodemográficos, hábitos de vida, condições de trabalho, padrões de sono, preferência diurna, perfil cronobiológico (cronotipo), morbidades referidas e relato de dores musculoesqueléticas. Na segunda etapa do estudo, observando critérios de exclusão, foram selecionados 62 trabalhadores (42 seringueiros e 20 operários). Nesta etapa, seringueiros e operários foram acompanhados por 21 dias e 10 dias, respectivamente, nos quais foram coletados dados referentes ao padrão de atividade/repouso (actimetria), exposição à luz e melatonina salivar. Resultados Os resultados da primeira etapa mostraram que os dias de trabalho e folga dos seringueiros são diferentes em relação aos horários de início, fim e duração de sono (p<0,01). Similarmente aos seringueiros, também foram observadas diferenças relativas aos padrões de sono (horários de início e fim), entre os operários, em todos os turnos estudados (matutino, vespertino e noturno), segundo dia de trabalho e dia de folga. A segunda etapa da pesquisa evidenciou que a presença de energia elétrica na residência teve efeito significativo no horário de início e duração de sono e no horário de início da secreção de melatonina dos seringueiros (p<0,01). Os seringueiros mostraram um adiantamento do horário de início da secreção de melatonina, padrão semelhante ao encontrado em parte dos operários, o que pode estar relacionado a uma maior tendência à matutinidade. Além disso, os seringueiros foram expostos à intensidade e período de luz (natural e artificial) maiores quando comparados aos trabalhadores da fábrica. Os operários apresentaram maiores escores de sonolência nos turnos matutino e noturno, sendo este último associado à ocorrência de distúrbios de sono e fadiga ao acordar. Conclusão A distinção observada entre os padrões de sono dos trabalhadores, segundo dias de trabalho e folga, tanto para seringueiros quanto trabalhadores da fábrica, sugere a relevância dos horários de trabalho no ciclo vigília-sono da população estudada. A presença de energia elétrica, assim como a exposição à luz (natural e artificial), revelaram papel significativo na expressão do sistema de temporização circadiana dos trabalhadores estudados.<br>Aim To investigate the association of working hours and light exposure patterns with the wake-sleep cycle and melatonin secretion of workers from the Chico Mendes Extractivist Reserve. Method A cross-sectional study was conducted in the city of Xapuri, Acre, involving 340 rubber tappers and 148 condom factory workers (46 administrative workers and 102 shop-floor operatives). The first stage of the study entailed collection, by questionnaire, of data on sociodemographic, life-style, working conditions, sleep patterns, daily preference, chronobiological profile (chronotype), and morbidities and musculoskeletal pains reported. In the second stage of the study, after applying exclusion criteria, a total of 62 workers (42 rubber tappers and 20 factory workers) were selected. In this stage, rubber tapper and factory workers were followed up for 21 days and 10 days, respectively. During the follow-up period, data was collected on activity/rest patterns (actimetry), light exposure, and melatonin levels in saliva. Results The results of the first stage revealed that the work days and days off of rubber tappers differed with regard to start, end and duration of sleep time (p<0.01). Akin to rubber tappers, differences in sleep patterns (start and end times) were also noted among the factory workers, across all shifts studied (morning, evening and night) for work days and days off. The second stage of the study found that having electricity available in the home had a significant effect on the start time and duration of sleep and on the start time of melatonin secretion of the rubber tappers (p<0.01). The rubber tappers exhibited an earlier start time for melatonin secretion, having a similar pattern to that found in some of the factory workers, possibly related to a greater tendency for morningness. In addition, rubber tappers were exposed to greater intensity and periods of light (natural and artificial) compared to the factory workers. The factory workers had higher sleepiness scores during morning and night shifts, with night shifts associated with the occurrence of sleep disturbance and fatigue at waking. Conclusion The differences in the workers´ sleep patterns between work days and days off observed for both rubber tappers and factory workers suggest an influence of working hours on the wake-sleep cycle of the population studied. Presence of electricity, as well as exposure to light (natural and artificial), had an important role in the expression of the circadian rhythm/timing system of the workers studied.
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Tavares, Gracilene Rodrigues. "Funcionalidade em pacientes ap?s acidente vascular encef?lico: rela??o com o sono e ritmo de atividade-repouso." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16685.
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Previous issue date: 2010-08-27<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior<br>It is known that sleep plays an important role in the process of motor learning. Recent studies have shown that the presence of sleep between training a motor task and retention test promotes a learning task so than the presence of only awake between training and testing. These findings also have been reported in stroke patients, however, there are few studies that investigate the results of this relationship on the functionality itself in this population. The objective of this study was to evaluate the relationship between functionality and sleep in patients in the chronic stage of stroke. A cross-sectional observational study was conducted. The sample was composed of 30 stroke individuals in chronic phase, between 6 and 60 months after injury and aged between 55 and 75 years. The volunteers were initially evaluated for clinical data of disease and personal history, severity of stroke, through the National Institute of Health Stroke Scale, and mental status, the Mini-Mental State Examination. Sleep assessment tools were Pittsburgh Sleep Quality Index, the Questionnaire of Horne and Ostberg, Epworth Sleepiness Scale, the Berlin questionnaire and actigraphy, which measures were: real time of sleep, waking after sleep onset, percentage of waking after sleep onset, sleep efficiency, sleep latency, sleep fragmentation index, mean activity score. Other actigraphy measures were intraday variability, stability interdi?ria, a 5-hour period with minimum level of activity (L5) and 10-hour period with maximum activity (M10), obtained to evaluate the activity-rest rhythm. The Functional Independence Measure (FIM) and the Berg Balance Scale (BBS) were the instruments used to evaluate the functional status of participants. The Spearman correlation coefficient and comparison tests (Student's t and Mann-Whitney) were used to analyze the relationship of sleep assessment tools and rest-activity rhythm to measures of functional assessment. The SPSS 16.0 was used for analysis, adopting a significance level of 5%. The main results observed were a negative correlation between sleepiness and balance and a negative correlation between the level of activity (M10) and sleep fragmentation. No measurement of sleep or rhythm was associated with functional independence measure. These findings suggest that there may be an association between sleepiness and
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balance in patients in the chronic stage of stroke, and that obtaining a higher level of activity may be associated with a better sleep pattern and rhythm more stable and less fragmented. Future studies should evaluate the cause-effect relationship between these parameters<br>Sabe-se que o sono exerce um importante papel no processo de aprendizado motor. Estudos recentes demonstraram que a presen?a do sono entre o treino de uma tarefa motora e o teste de reten??o promove um aprendizado da tarefa de forma superior ? presen?a apenas de vig?lia entre treino e teste. Estes achados tamb?m t?m sido encontrados em pacientes que sofreram acidente vascular encef?lico (AVE), entretanto, faltam estudos que investiguem os resultados desta rela??o sobre a funcionalidade propriamente dita nesta popula??o. O objetivo desta pesquisa foi verificar a rela??o entre capacidade funcional e sono em pacientes em est?gio cr?nico de acidente vascular encef?lico. Foi realizado um estudo observacional anal?tico transversal. A amostra foi composta por 30 indiv?duos com seq?elas motoras de AVE em fase cr?nica, faixa et?ria entre 55 e 75 anos, apresentando tempo de seq?ela entre 6 e 60 meses. Os volunt?rios foram inicialmente avaliados quanto aos dados cl?nicos e antecedentes pessoais, severidade do AVE, atrav?s da escala internacional de AVE do National Institute of Health, e estado mental, pelo Mini-Exame do Estado Mental. Os instrumentos de avalia??o do sono foram o ?ndice de Qualidade do Sono de Pittsburgh, o question?rio de Horne e Ostberg, Escala de Sonol?ncia de Epworth (ESE), o question?rio de Berlim e a actimetria, cujas medidas utilizadas foram: tempo real de sono, tempo de vig?lia ap?s o in?cio do sono, porcentagem de tempo de vig?lia ap?s o in?cio do sono, efici?ncia do sono, lat?ncia para o sono, ?ndice de fragmenta??o do sono, m?dia do escore de atividade. Outras medidas da actimetria foram a variabilidade intradi?ria, estabilidade interdi?ria, per?odo de 5 horas com n?vel m?nimo de atividade (L5) e per?odo de 10 horas com n?vel m?ximo de atividade (M10), obtidas para avalia??o do ritmo de atividade-repouso. A Medida de Independ?ncia Funcional (MIF) e a Escala de Equil?brio de Berg (EEB) foram os instrumentos utilizados para avalia??o da condi??o funcional dos participantes. O coeficiente de correla??o de Spearman e testes comparativos (t de student e Mann-Witney) foram utilizados para an?lise da rela??o dos instrumentos de avalia??o do sono e do ritmo de atividade/repouso com as medidas de avalia??o funcional. O programa estat?stico SPSS 16.0 foi empregado para as an?lises, adotando-se n?vel de signific?ncia de 5%. Os principais resultados observados foram uma correla??o negativa entre sonol?ncia e equil?brio e uma correla??o negativa entre o n?vel de atividade (M10) e fragmenta??o do sono. Nenhuma medida do sono ou do ritmo foi associada com a medida de independ?ncia funcional. Estes achados sugerem que pode haver uma associa??o entre sonol?ncia e equil?brio em pacientes em est?gio cr?nico de AVE, e ainda que a obten??o de um maior n?vel de atividade pode estar associada a um melhor padr?o de sono e ritmo mais est?vel e menos fragmentado. Futuros estudos devem avaliar a rela??o de causa-efeito entre estes par?metros
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Burgos, Leana Gonçalves Araujo. "Efeitos do trabalho noturno nos ritmos circadianos de marcadores do processo inflamatório." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-18112015-102240/.
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Introdução: Uma das reconhecidas consequências do trabalho noturno nos trabalhadores é a perda da ordem temporal interna, a qual resulta em alterações fisiopatológicas. Objetivo: O presente estudo teve o objetivo de avaliar os efeitos do turno noturno de traballho na concentração e no ritmo circadiano de citocinas inflamatórias de trabalhadores de linha de produção e operadores de máquinas. Material e Métodos: Estudo transversal realizado em uma empresa do setor de bebidas. Na Etapa 1 foram avaliados em 123 trabalhadores (56 do turno fixo diurno e 67 do turno fixo noturno), dados sociodemográficos, condições de vida e lazer, condições e organização do trabalho, morbidades, sintomas osteomusculares, fadiga, sonolência excessiva e dados antropométricos. Quinze voluntários do turno diurno, 15 do turno noturno em período de trabalho e em momento de férias participaram da Etapa 2. Durante sete dias foram coletados dados do padrão de sono e vigília e em um Dia de Trabalho e um Dia de Folga foram realizadas coletas salivares em intervalos de três horas, durante a vigília, para estimar a concentração de melatonina, IL-1 e IL-6, além de coletados dados de sonolência, fadiga e dor. Também foi realizada coleta de urina para medir 6-sulfatoximelatonina após o episódio principal de sono. Foram verificadas diferenças de médias entre os dados dos grupos obtidos na Etapa 1, assim como análises de Odds Ratio. A ANOVA Nested foi utilizada na Etapa 2 para comparar os grupos (Diurno, Noturno e Noturno-Férias), seguida do teste de contraste de Dunnet. A Etapa 3 comparou a curva das citocinas IL-1, IL-6 e TNF- na saliva e no sangue em 7 indivíduos saudáveis em laboratório. O método do Cosinor individual e populacional foi aplicado para verificar ritmicidade circadiana. Resultados: Os resultados revelaram que os trabalhadores noturnos tinham menor amplitude do ritmo da melatonina salivar que os diurnos. Embora a concentração de 6-sulfatoximelatonina também tenha sido menor entre os trabalhadores noturnos comparados com os diurnos, sua concentração foi mais elevada durante as férias. Nas férias se observou um aumento da duração do sono, apesar de não ter sido verificada nenhuma diferença entre os parâmetros do sono principal e do cochilo entre os trabalhadores dos turnos diurnos e noturno no período de trabalho. No entanto, a acrofase da citocina IL-6 ocorreu em horário similar nos três grupos, ainda que os trabalhadores noturnos tenham apresentado maior concentração dessa citocina. A IL-1 apresentou ritmicidade apenas para o grupo diurno. Não houve diferença na prevalência de doenças entre os Grupos Diurno e Noturno. Os dados com os indivíduos em laboratório com ambiente controlado demonstraram ausência de ritmicidade da IL-1 e presença de ritmicidade da IL-6 tanto no sangue quanto na saliva. Conclusão: Trabalhadores noturnos estavam dessincronizados e apresentaram privação parcial de sono. O período de férias levou ao aumento da duração do sono; aumento da secreção de melatonina medida pela 6-sulfatoximelatonina, além da diminuição da sonolência, fadiga, dor e concentração de IL-1. Esses achados evidenciam as consequências negativas na saúde que o turno noturno de trabalho pode ocasionar e demonstram que há parcial reversão desses efeitos nas férias.<br>Introduction: A recognized consequence of night shift work on employees is the loss of internal temporal order, which results in pathophysiological alterations. Objective: This study aimed to evaluate the effects of night shift work on the level and circadian rhythm of inflammatory cytokines of line workers and machine operators. Methods: A cross-sectional study was conducted in a beverage company. On stage 1 of the study, demographic data, living and leisure conditions, work conditions and organization, morbidity, musculoskeletal symptoms, fatigue, excessive sleepiness and anthropometric data of 123 workers (56 fixed day workers and 67 fixed night shift workers) were evaluated. Fifteen volunteers from day shift, 15 from night shift, and 15 from the same night shift during vacation participated in stage 2. During seven consecutive days, data were collected regarding the pattern of sleep and wakefulness. Also, on one work day and one day off, within this 7 days, saliva samples were collected every three hours while subjects were awake to evaluate melatonin, IL-1 and IL-6, in addition to drowsiness, fatigue and pain data were also collected. Furthermore, urine samples were collected to measure 6-sulphatoxymelatonin after the main sleep episode. Mean differences between groups and analysis of Odds Ratio were used to evaluate the data collected on stage 1. For the analysis of data collected on stage 2, Nested ANOVA followed by Dunnet contrast test were used in order to compare the three groups (Day, Night and Night-vacation). On stage 3, salivary and blood IL-1, IL-6 and TNF- citokine curves from seven healthy subjects kept in a controled laboratory environment were compared. Individual and populational Cosinor was the method used to verify circadian rhythmicity in stage 2 and 3. Results: The results showed that night workers had lower amplitude of the rhythm of salivary melatonin then day workers. Although the concentration of 6-sulphatoxymelatonin was lower among night shift workers compared to day workers, its concentration was higher during vacation time. During vacation, an increase in sleep duration was observed, even though no differences between the main parameters of sleep and nap between day and night workers during work period were found. However, the IL-6 cytokine acrophase occurred in similar periods among the three groups, even though the night shift workers had a higher concentration of this cytokine. The IL-1 showed rhythmicity only for day workers. There was no difference in the prevalence of diseases among day and night workers. The data collected from healthy subjects in controlled environment showed absence of rhythmicity for IL-1, but presence of rhythmicity for IL-6 present in both blood and saliva. Conclusion: Night shift workers were desynchronized and showed signs of partial sleep deprivation. During vacation, sleep duration was increased; melatonin secretion measured by the 6-sulphatoxymelatonin was increased, in addition to decreased drowsiness, fatigue, pain and concentration of IL-1. These findings highlight the negative health consequences that night shift work can cause and show that there are partial reverse effects of these changes during vacation.
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Souza, Jane Carla de. "Caracteriza??o do ciclo sono/vig?lia de professores do ensino m?dio em natal/rn." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17296.
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Previous issue date: 2010-05-04<br>Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico<br>In the school environment is fundamental the knowledge about the sleep-wake cycle (SWC), because we find children and adolescents with excessive sleepiness and learning difficulties. Furthermore, teachers with high demand and with different work schedule, which may contribute to changes in SWC. The aim of this study was to describe the SWC of high school teachers in Natal/RN. Habits and knowledge about sleep, chronotype, SWC, daytime sleepiness, sleep quality and job satisfaction were described in 98 high school teachers from public and private school. These parameters were compared according to the characteristics of work, family structure and gender. Data collection was performed with the use of questionnaires in two stages: 1) "health and sleep" (general characterization of sleep habits), Horne & Ostberg questionnaire (characterization of chronotype), Epworth Sleepiness Scale and the Index of Pittsburg Sleep Quality, 2) The sleep diary for 14 days. From the results, we observe that the teachers woke up and went to bed earlier in the week and showed a reduction of time in bed around 42min comparing to weekend. This reduction in time in bed during the week was accompanied by an increase in nap duration on weekend. In addition the teachers woke up earlier on Saturdays than on Sundays, probably due to housework and leisure. The teachers' knowledge about sleep was low in relation to individual differences and effect of alcoholic beverages on sleep, and high in the consequences of sleep deprivation. The differences found in comparisons on the characteristics of work, family structure and gender were punctual, except concerning the work schedule. The teacher who started work in the morning and finished in the night, woke up earlier, went to bed later and had less time in bed, when compared to teachers who work only in two shifts. In addition, teachers with late chronotypes who begin the work in the morning had a greater irregularity in the wake up time compared to teachers with earlier and intermediate chronotypes. Half of teachers have excessive sleepiness, which was positive correlated with work dissatisfaction. In general, teachers showed IPSQ averages equivalent to poor sleep quality and the women showed worst averages. From the results, it is suggested that the SWC of teachers varies according to work schedule, leading to irregularity and partial sleep deprivation in the week, although these responses vary according to chronotype. These changes are accompanied by excessive daytime sleepiness and poor sleep quality. However, it is necessary to expand the sample to clarify the influence of variables related to work, family structure and gender together<br>No ambiente escolar ? de fundamental import?ncia o conhecimento sobre o ciclo sono e vig?lia (CSV), pois encontramos crian?as e adolescentes com sonol?ncia excessiva e dificuldades de aprendizagem, al?m de professores com alta demanda e hor?rio diferenciado de trabalho, o que pode contribuir para o surgimento de altera??es no CSV. O objetivo deste estudo foi caracterizar o CSV de professores do ensino m?dio de Natal/RN. Participaram da pesquisa 98 professores de escolas p?blicas e privadas, dos quais, foram descritos os h?bitos e conhecimentos sobre o sono, cronotipo, padr?o do CSV, n?veis de sonol?ncia diurna, qualidade do sono e satisfa??o profissional, comparando estas vari?veis quanto ?s caracter?sticas de trabalho, estrutura familiar e g?nero. A coleta de dados foi realizada com a aplica??o de question?rios em duas etapas: 1) sa?de e o sono (caracteriza??o geral dos h?bitos de sono); question?rio de Horne & Ostberg (caracteriza??o do cronotipo); Escala de Sonol?ncia de Epworth e o ?ndice de Qualidade do Sono de Pittsburg; 2) O di?rio de sono durante 14 dias. A partir dos resultados, observamos que os professores levantaram e deitaram mais cedo e apresentaram uma redu??o do tempo na cama em torno de 42min na semana quando comparada ao fim de semana. Esta redu??o no tempo na cama na semana foi acompanhada por uma maior dura??o do cochilo no fim de semana. Al?m disso, os professores levantaram aos s?bados mais cedo que aos domingos, provavelmente devido aos afazeres dom?sticos e lazer. O conhecimento dos professores sobre o sono foi baixo com rela??o ?s diferen?as individuais e o efeito de bebidas alco?licas sobre o sono e alto em rela??o ?s consequ?ncias da priva??o do sono. As diferen?as encontradas nas compara??es quanto ?s caracter?sticas de trabalho, estrutura familiar e g?nero foram pontuais, exceto com rela??o ao hor?rio de trabalho. Os professores que iniciavam o trabalho pela manh? e finalizavam ? noite levantaram mais cedo, dormiram mais tarde e apresentaram menor tempo na cama, em rela??o aos que trabalhavam apenas em dois turnos. Al?m disso, entre os professores que iniciavam o trabalho pela manh? e que foram classificados como vespertinos houve uma maior irregularidade no hor?rio de levantar em rela??o aos matutinos e intermedi?rios. Metade dos professores apresentou sonol?ncia excessiva, que teve correla??o positiva com a insatisfa??o com o trabalho. Em geral, os professores apresentaram m?dias do IQSP equivalentes ? m? qualidade de sono, tendo as mulheres piores m?dias. A partir dos resultados, sugere-se que o CSV dos professores varia de acordo com o hor?rio de trabalho, acarretando em irregularidade no CSV e priva??o de sono durante a semana, embora o efeito sobre irregularidade varie em fun??o do cronotipo. Estas altera??es s?o acompanhadas de sonol?ncia excessiva diurna e m? qualidade de sono. Por?m, faz-se necess?rio ampliar a amostra para esclarecer a influ?ncia das vari?veis relacionadas ao trabalho, ? estrutura familiar e g?nero em conjunto
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Ghosh, Sagnik. "Les phéromones sexuelles redéfinissent les rythmes quotidiens d'activité et de repos des insectes." Electronic Thesis or Diss., université Paris-Saclay, 2025. http://www.theses.fr/2025UPASB007.
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Les cycles activité-repos sont des comportements conservés chez tous les animaux dotés d'un système nerveux, de l'hydre à l'homme. Le schéma temporel de ces cycles varie, rendant les animaux diurnes, nocturnes ou crépusculaires. Leur orchestration repose sur l'horloge circadienne, qui fonctionne sur une période de près de 24 heures et dicte les moments de sommeil et d'éveil. Des signaux abiotiques comme la lumière et la température ajustent quotidiennement ces rythmes. Ici, nous avons étudié si les interactions sociosexuelles cycliques pouvaient constituer un zeitgeber biotique puissant chez les insectes. Pour cela, nous avons utilisé le papillon de nuit solitaire Spodoptera littoralis et la mouche Drosophila melanogaster. Chez la plupart des insectes, les phéromones sexuelles jouent un rôle clé dans la communication sociale entre les conspécifiques. Qu'elles soient volatiles (olfactives) ou spécifiques au contact (gustatives), les phéromones sexuelles régulent les interactions sociosexuelles, une forme élémentaire de comportement social chez les insectes. Nous avons émis l'hypothèse que l'exposition aux phéromones sexuelles pouvait étendre son effet au-delà des voies chimiosensorielles canoniques du cerveau pour moduler les cycles d'activité et de repos des insectes. Chez les papillons de nuit mâles solitaires, nous avons montré que les interactions socio-sexuelles à distance médiées par les phéromones influencent les rythmes circadiens. L'horloge circadienne des femelles régule la libération périodique de phéromones sexuelles, et cette disponibilité rythmique induit et synchronise les cycles activité-repos des mâles en modulant l'expression des gènes horloges. Nos résultats révèlent une relation hiérarchique entre les horloges circadiennes des femelles et des mâles, suggérant que la temporalité est un trait soumis à la sélection sexuelle. Fait remarquable, l'impact de la phéromone peut annuler l'effet de la lumière sur l'horloge chez le papillon de nuit, ce qui constitue un modèle unique d'entraînement chimiosensoriel de l'horloge en chronobiologie. Dans le mélange phéromonal des femelles, nous avons identifié des composants qui ne sont pas sexuellement attractifs pour les mâles mais qui ont de forts effets circadiens. Ces volatiles, partagés entre espèces sympatriques, peuvent induire une synchronisation communautaire. Chez les mouches, les signaux féminins modifient également les cycles d'activité-repos. Chez D.melanogaster, nous avons découvert un changement de niche temporelle induit par les phéromones. En effet, les mouches qui sont crépusculaires quand elles sont seules deviennent nocturnes en groupe et cela a été observé tant en laboratoire qu'en milieu semi-naturel. Même un couple hétérosexuel isolé présente un pic d'activité locomoteur nocturne important. Or, contrairement aux papillons de nuit, cette modulation chez les mouches fonctionne indépendamment de l'horloge circadienne via des voies d'éveil dépendantes de la dopamine. Les souches sauvages de D.melanogaster présentent des différences qualitatives et quantitatives dans les profils de phéromones sexuelles selon leur origine biogéographique. Ces différences sont corrélées avec les variations de la nocturnité, qui sont plus prononcées chez les mouches européennes des latitudes plus élevées. De plus, nous avons révélé que différentes espèces de Drosophiles changent de niche temporelle à des moments distincts de la journée, le choix du moment étant influencé par leur dépendance relative à l'égard des indices visuels ou gustatifs pour les interactions sociosexuelles. Nos résultats, à l'interface entre la neuroscience et l'écologie chimique, montrent que les interactions écologiques modulent des comportements génétiquement programmés comme le sommeil. Ils soulignent aussi l'importance des études comparatives sur des insectes non modèles ayant une spécialisation sensorielle unique pour une compréhension plus profonde et plus large de la neuroéthologie circadienne<br>Cyclic rest-activity patterns are conserved behaviors in all animals with a nervous system, from hydra to humans. The temporal pattern of rest-activity cycles varies, rendering animals diurnal, nocturnal, or crepuscular. The patterning of these cycles is orchestrated by the circadian clock, which operates with a nearly 24-hour period, dictating the timing of sleep and wakefulness. External abiotic cues such as light and temperature fine-tune these rhythms daily. Here, we investigated whether cyclic sociosexual interactions can serve as a potent biotic zeitgeber for the insects. To address this, we employed the solitary adult moth Spodoptera littoralis and the gregarious vinegar fly Drosophila melanogaster.In most insects, chemical signals like pheromones act as powerful cues for social communication among conspecifics. Sex pheromones, which can be either volatile (olfactory) or contact-specific (gustatory), mediate sociosexual interactions—an elementary form of social behavior common to all insects. We hypothesized that sex-pheromone exposure could extend its influence beyond canonical chemosensory pathways in the brain, modulating the insects' rest-activity cycles over time.In solitary male moths, we revealed that remotely occurring, pheromone-mediated sociosexual interactions exert a surprisingly strong influence on free-running circadian rhythms. The females' circadian clock regulates the periodic release of sex pheromones, and the rhythmic availability of these pheromones induces and synchronizes males' rest-activity cycles by modulating their clock gene expression. Our findings highlight a hierarchical relationship between female and male circadian oscillators and imply that timing is a sexually selected trait. Remarkably, the impact of pheromonal cues on the moth clock can even supersede the entraining effect of light, establishing a unique model for chemosensory clock entrainment in chronobiology. Within the female moth's sex-pheromone blend, we identified specific components that lack mate-attractive properties but exert powerful circadian effects. These volatiles, shared across sympatric moth species, can trigger communal synchronization.Female cues also influence rest-activity patterns in fruit flies. In D. melanogaster, we uncovered sex pheromone-driven temporal niche switching, whereby singly crepuscular flies become nocturnal when in groups under both laboratory and semi-natural outdoor conditions. Even an isolated heterosexual pair display a prominent peak of locomotor activity in the middle of the night. However, unlike in moths, the modulation of rest-activity patterns by sex pheromones in flies operates independently of the circadian clock, acting instead via dopamine-dependent arousal pathways. Wild strains of D. melanogaster, depending on their biogeographic origin, display qualitative and quantitative differences in sex pheromone profiles. These differences correlate with variations in nocturnality, which are more pronounced in higher-latitude European flies. Furthermore, we revealed that different Drosophila species exhibit temporal niche switching at distinct times of the day, with the choice of timing influenced by their relative reliance on visual versus gustatory cues for sociosexual interactions.Our results, at the interface of neuroscience and chemical ecology, demonstrate that ecological interactions can modulate genetically programmed behaviors like sleep. They highlight that comparative studies using non-model insects endowed with unique sensory specializations should pave the way for a deeper and broader understanding of circadian neuroethology
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Pegado, Jo?o Felipe de Souza. "Diferen?as de g?nero na produ??o de associa??es livres de palavras atrav?s do ciclo sono-vig?lia." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13389.
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Previous issue date: 2012-04-20<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior<br>Although several studies, have shown differences in cognitive performance
between men and women, it not yet known whether these differences occur in
tasks involving free association of words (WA). Studies across the sleep-wake
cycle (SWC) suggest that rapid eye movement sleep (REM) favors semantic
flexibility, in comparison with pre-sleep waking (Pre-WK), slow-wave sleep (SWS)
and post-sleep waking (Post-WK). The present work has two aims: (1) to evaluate
the semantic distances of word pairs produced by AP, comparing men and
women, (2) to evaluate semantic distance in word pairs produced by free
association across the SWC in young adults of both sexes. To achieve aim (1), we
applied a task of WA in 68 adult volunteers during waking (52 women and 16
men). The WA task consisted of writing the first word that came to mind after
viewing another word offered as a stimulus (root Word). To achieve aim (2), we
performed polysomnography to identify specific stages of the SWC. The
experimental subjects were then awakened (if they were asleep) and were
immediately given a WA task. The task was administered to 2 groups of 10
subjects each (G1 and G2). G1 subjects were stimulated with the same set of root
words after waking from various states of SWC, while G2 subjects received sets of
different root words at each state of the SWC. In the absence of a Portuguese
corpus suitable for the measurement of semantic distances, the words collected in
our experiments were translated to English, and semantically quantified within a
systematic and representative corpus of that language (Wordnet). This procedure
removed the polysemies typical of Portuguese, but preserved the semantic macrostructure
common to both languages. During waking, we found that semantic
distances are significantly lower in WA produced by women, in comparison with
the distances observed in men. Through the SWC, there were no statistically
significant differences in G1. In G2 women, we detected a significant increase of
semantic distances upon being awakened from SWS. In contrast, G2 men showed
a significant increase in semantic distances upon being awakened from REM. The
results of the first experiment are consistent with the notion that women have a
more concrete reasoning than men. The results of the second experiment indicate
that men awakened from REM present more flexibility in word association than
when being awakened from other states. In contrast, women showed more flexible
word association after being awakened from SWS, in compared with other states.
The results indicate that the cognitive flexibility attributed to different states of the
SWC shows gender dependency<br>Embora diversos estudos demonstrem diferen?as no desempenho
cognitivo, entre homens e mulheres, ainda n?o se sabe se essas diferen?as
ocorrem em tarefas que envolvam associa??o livre de palavras (AP). Estudos
atrav?s do ciclo sono-vig?lia (CSV) sugerem que o sono de movimento r?pido dos
olhos (MRO) favore?a a flexibilidade sem?ntica, em compara??o com a vig?lia pr?sono
(V-Pr?), o sono de ondas lentas (SOL) e a vig?lia p?s-sono (V-P?s). O
presente trabalho teve 2 objetivos: (1) Avaliar as dist?ncias sem?nticas de pares
de palavras produzidas por AP, comparando homens e mulheres; (2) Avaliar
dist?ncias sem?nticas em palavras produzidas por associa??o livre, atrav?s do
CSV em adultos jovens de ambos os sexos. Para alcan?ar o objetivo (1),
aplicamos uma tarefa de AP em 68 volunt?rios adultos durante a vig?lia (52
mulheres e 16 homens). A tarefa de AP consistiu em listar por escrito a primeira
palavra pensada ap?s visualizar outra palavra oferecida como est?mulo. Para
alcan?ar o objetivo (2), realizamos registro polissonogr?fico para identificar fases
espec?ficas do CSV. Os sujeitos experimentais foram ent?o despertados (caso
estivessem em sono) e foram imediatamente submetidos a uma tarefa de AP.
Administrou-se a tarefa de AP a 2 grupos de 10 pessoas cada (G1 e G2). Sujeitos
de G1 foram estimulados com o mesmo conjunto de palavras-raiz ap?s despertar
dos diversos estados do CSV, enquanto que sujeitos de G2 receberam conjuntos
de palavras-raiz diferentes a cada estado do CSV. Na aus?ncia de um corpus em
portugu?s adequado para ? mensura??o de distancias sem?nticas, as palavras
coletadas foram traduzidas para o idioma ingl?s, e semanticamente quantificadas
em um corpus representativo e sistem?tico desse idioma (Wordnet). Esse
procedimento retirou as polissemias t?picas do portugu?s, mas preservou a
macroestrutura sem?ntica comum ?s duas l?nguas. Na vig?lia, verificamos que as
dist?ncias sem?nticas s?o significativamente menores nas AP produzidas por
mulheres, em compara??o com as dist?ncias sem?nticas verificadas em AP
realizadas por homens. Atrav?s do CSV, n?o foram detectadas diferen?as
estatisticamente significativas em G1. Em mulheres de G2, detectamos um
aumento significativo das dist?ncias sem?nticas ap?s despertar de SOL. Em
contraste, homens de G2 apresentaram um aumento significativo das dist?ncias
sem?nticas ap?s despertar de MRO. Os resultados do primeiro experimento s?o
compat?veis com a no??o de que as mulheres possuem um racioc?nio mais
concreto do que homens. Os resultados do experimento 2 indicam que homens
despertados durante o MRO apresentam AP mais flex?veis em compara??o com
as AP produzidas ap?s vig?lia ou ap?s despertar de SOL. Mulheres apresentaram
resultados distintos, com AP mais flex?vel ap?s despertar de SOL, em
compara??o com os outros estados. Os resultados indicam que a flexibilidade
cognitiva atribu?da a diferentes estados do CSV apresenta depend?ncia de
g?nero
31
Xavier, Rafaella Kaline Costa. "Rela??o entre o ciclo sono e vig?lia e a fun??o cardiorrespirat?ria em estudantes de medicina." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17309.
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Previous issue date: 2010-10-08<br>Students, normally, present an irregular sleep pattern characterized by delays in
sleep onset and offset from weekdays to weekends, short sleep duration on
weekdays and long sleep duration on weekends. The reduction of the necessary
sleep and the irregularity in the sleep patterns provoke relevant short- and long-term
impairments on performances, for example, in cardiorespiratory function. The
cardiorespiratory performance represents, in addition to fitness, traces associated to
health conditions and in several studies to pattern and/or individual s sleep quality.
The aim of this study was to evaluate the pattern of the sleep-wake cycle and the
cardiorespiratory function of medical students under different class schedules. The
study was accomplished with two classes of medical students of UFRN, one had
classes at 7 am (n = 47) and the second had classes at 8 am (n = 41) during the
week. On the first stage of the study all volunteers filled out an anamnesis, the
International Physical Activity questionnaire, the Pittsburgh index of sleep quality, the
Portuguese version of the Horne and ?stberg cronotype questionnaire, the Health
and Sleep questionnaire and the Epworth Scale of Somnolence (ESS). On the
second stage, 24 students (12 of each class) had their activity rhythm monitored by
actimeters set to record activity at a 2-min interval for 14 days concomitant to the
completion of the sleep diary. In this same stage, each volunteer performed the effort
test (treadmill) only once in the morning period (between 9:00 and 11:00). The
students showed an irregular pattern of the sleep-wake cycle and this irregularity is
strongly influenced by the class schedules, in addition to the contribution of the
academic demand, social activities and endogenous factors. The students who woke
up earlier showed greater irregularity in the sleep-wake pattern. The earlier was the
class schedule the worse was the sleep quality and the greater was the frequency of
students with excessive diurnal somnolence. The classes schedules and the
irregular pattern of the sleep-wake cycle did not show effect on the cardiorespiratory
performance of the medical students. The performance on the test seems to be
affected by other factors, which can be related to the pattern of the sleep-wake cycle
or not. Therefore, it is suggested that the late start of classes provokes less
irregularity on the pattern of the sleep-wake cycle. However, it was observed that this
irregularity and the class schedule seem not to affect the cardiorespiratory
performance directly<br>Os estudantes, normalmente, apresentam um padr?o de sono irregular
caracterizado por atrasos de in?cio e final do sono dos dias de semana para os finais
de semana, curta dura??o de sono nos dias de semana e longa dura??o de sono
nos finais de semana. A redu??o do sono necess?rio na semana e a consequente
irregularidade no ciclo sono e vig?lia (CSV) provocam detrimentos relevantes a curto
e longo prazo no desempenho dos estudantes, como por exemplo, na fun??o
cardiorrespirat?ria. O condicionamento cardiorrespirat?rio representa al?m do
condicionamento f?sico, tra?os associados ?s condi??es de sa?de e, em muitos
estudos, no padr?o e/ou qualidade do sono de um indiv?duo. O objetivo desse
estudo foi avaliar o padr?o do ciclo sono e vig?lia e a fun??o cardiorrespirat?ria de
estudantes de medicina em diferentes esquemas de hor?rios de aulas. O estudo foi
realizado com duas turmas de estudantes de medicina da UFRN, uma assistia aula
?s 7h (n=47) e a outra assistia aula ?s 8h (n=41) durante a semana. Na 1? etapa do
estudo todos os volunt?rios responderam uma anamnese, o Question?rio
Internacional de Atividade F?sica, o ?ndice de Qualidade do Sono de Pittsburgh, a
vers?o em portugu?s do question?rio de Cronotipo de Horne e ?stberg, o
question?rio a Sa?de e o sono e a escala de sonol?ncia de Epworth. Na segunda
etapa, 24 alunos (12 de cada turma) tiveram o ritmo de monitorado por act?metros
com 2min de intervalo, por 14 dias, concomitante ao preenchimento do di?rio do
sono. Nesse mesmo per?odo, cada volunt?rio fez o teste de esfor?o (esteira
ergom?trica) uma ?nica vez, sempre no per?odo da manh? (entre 9h e 11h). Os
estudantes apresentam um padr?o irregular do CSV e essa irregularidade e
fortemente vinculada aos hor?rios de aula, al?m da contribui??o da demanda
acad?mica, atividades sociais e fatores end?genos. Os alunos que acordam mais
cedo apresentam maior irregularidade no padr?o de CSV. Quanto mais cedo o
hor?rio de aulas pior a qualidade do sono e maior a frequ?ncia de estudantes com
sonol?ncia diurna excessiva. Os hor?rios de aula e o padr?o irregular do CVS n?o
mostraram efeito sob o desempenho cardiorrespirat?rio dos estudantes de medicina.
O desempenho no teste parece ser afetado por outros fatores, que podem ser
relacionados ao padr?o do CSV ou n?o. Assim, sugere-se que o in?cio tardio das
aulas provoca menor irregularidade no padr?o do CSV, por?m, observou-se que
essa irregularidade e o hor?rio de aula parece n?o afetar a desempenho
cardiorrespirat?rio diretamente
32
Bazilio, Darlan da Silva. "Avaliação de parâmetros cardiovasculares e respiratórios durante o ciclo sono-vigília de ratos submetidos à hipóxia crônica intermitente." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17134/tde-23072018-102108/.
Full textAbstract:
A hipóxia crônica intermitente (HCI) é um modelo experimental no qual o quimiorreflexo é ativado a cada episódio de hipóxia, assim como em alguns casos de apneia obstrutiva do sono. A HCI promove aumento da atividade simpática, hipertensão e alterações no acoplamento simpático-respiratório no tronco encefálico. No presente trabalho estudamos os parâmetros cardiorrespiratórios concomitantemente com o ciclo sono-vigília em uma janela temporal de 3 horas no período do dia em que esses registros são feitos no nosso laboratório. Foram também registradas ao longo deste período as respostas cardiovasculares associadas a inspirações profundas (IPs) que acontecem normalmente nos ratos. Ratos Wistar (~ 250 g) foram divididos nos grupos HCI (n = 12) e controle (CTL) (n = 12). Os animais foram submetidos à cirurgia de implantação de eletrodos no crânio e nos músculos cervicais para obtenção de registros eletrocorticográficos (ECoG) e eletromiográficos (EMG), respectivamente, para determinarmos as fases do ciclo sono-vigília (vigília, sono NREM (non-rapid eye movement) e sono REM (rapid eye movement)). Um grupo de animais CTL (n=5) e outro de animais HCI (n=6) tiveram também eletrodos implantados nos músculos diafragma (DIA) e abdominal oblíquo (ABD) para registros da atividade muscular respiratória. Após 48 horas, o grupo HCI foi exposto a um protocolo de hipóxia intermitente durante 10 dias (6% de O2 por 40 s, a cada 9 min, 8 h/d), enquanto o grupo CTL foi mantido em normoxia (20,8% de O2) pelo mesmo período. No último dia do protocolo, os ratos tiveram uma artéria femoral canulada para registros de pressão arterial (PA). No dia seguinte, ECoG, EMG e a PA foram registrados por 3 horas para análise da latência para o sono, o tempo total em cada uma das fases do ciclo sonovigília, o número e a duração dos episódios de sono REM e os parâmetros cardiovasculares pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), pressão arterial média (PAM) e frequência cardíaca (FC) nas diferentes fases do ciclo. Os parâmetros respiratórios foram registrados por 2 horas para análise de frequência respiratória (fR), volume corrente (VT) e volume minuto (VE) nas diferentes fases do ciclo sono-vigília. Os animais dos grupos utilizados para avaliação da atividade respiratória muscular foram registrados por 2 horas. O protocolo de 10 dias de HCIpromoveu alterações significativas apenas na duração dos episódios de sono REM nos ratos HCI. Entretanto, os animais do grupo HCI apresentaram níveis médios mais elevados de PAS (145,0 ± 1,8 vs 129,3 ± 2,2 mmHg), PAD (104,1 ± 1,7 vs 91,4 ± 1,8 mmHg), PAM (121 ± 9 vs 107,7 ± 1,9 mmHg) e FC (387, ± 5,4 vs 363,5 ± 8,7 bpm) no período de 3 horas de registro, sendo estes aumentos igualmente observados em todas as fases do ciclo sono-vigília. A HCI também promoveu aumento significativo de VT durante os sonos NREM (6,6 ± 0,2 vs 5,8 ± 0,2 mL/kg) e REM (6,4 ± 0,2 vs 5,3 ± 0,2 mL/kg), porém este parâmetro não foi significativamente diferente durante a vigília nos animais HCI em relação aos animais CTL. Ambos os grupos apresentaram expirações ativas apenas durante a vigília, porém estas foram muito mais frequentes nos animais HCI. Além disso, nos animais HCI as respostas de queda da PAM (-18 ± 0,8 vs -14 ± 0,6 mmHg) e aumento da FC (28,4 ± 1,8 vs 21,8 ± 1,1 bpm) associadas às IPs apresentaram maiores magnitudes em relação aos animais CTL, embora o intervalo temporal entre as IPs não tenha se alterado. Esses achados indicam que a HCI aplicada durante 10 dias promove alterações significativas na duração dos episódios de sono REM, aumento da PA e FC em todas as fases do ciclo sono-vigília, aumento do VT durante o sono, aumento da ocorrência de expirações ativas durante a vigília e aumento das respostas hemodinâmicas associadas às IPs. Portanto, as alterações cardiovasculares observadas após a HCI são decorrentes dos episódios repetidos de hipóxia que acontecem ao longo desse protocolo, mas não parecem ser dependentes de alterações no ciclo sono-vigília, pois ainda que a duração dos episódios de sono REM tenha sido maior nos ratos HCI, os parâmetros cardiovasculares se apresentaram igualmente elevados em todas as fases do ciclo sono-vigília desses animais.<br>Chronic intermittent hypoxia (CIH) is an experimental model in which the chemoreflex is activated at each episode of hypoxia, as observed in some cases of obstructive sleep apnea. CIH induces increased sympathetic activity, hypertension, and changes in the sympathetic-respiratory coupling in the brainstem. In the present study, we recorded cardiorespiratory parameters concomitantly with the sleep-wake cycle during a 3-hour time window which corresponds to the period of the day in which these recordings are collected in our laboratory. During this period, we also studied the cardiovascular responses associated with the normally occurring deep breaths (DBs) in rats. Male Wistar rats (~ 250 g) were divided into CIH (n = 12) and control (CTL) groups (n = 12). Animals underwent implantation of electrodes in the skull and in the cervical muscles for electrocorticographic (ECoG) and electromyographic (EMG) recordings, respectively, to determine the phases of the sleep-wake cycle (wakefulness, NREM sleep and REM sleep). A group of CTL animals (n=5) and another of HCI animals (n=6) had electrodes implanted also in the diaphragm (DIA) and oblique abdominal muscle (ABD) for recordings of respiratory muscle activity. After 48 hours, the CIH group was exposed to an intermittent hypoxia protocol for 10 days (6% O2 for 40 s, every 9 min, 8 h/d), while the CTL group was maintained in normoxia (20.8 % of O2) for the same period. On the last day of the protocol, rats had a femoral artery cannulated for blood pressure (BP) recordings. On the following day, ECoG, EMG and BP were recorded for 3 hours for analysis of time for sleep onset, total time in each phase of the sleep-wake cycle, number and duration of REM sleep episodes, and the cardiovascular parameters systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and heart rate (HR) in the different phases of the cycle. The respiratory parameters were recorded for 2 hours for analysis of ventilatory frequency (fR), tidal volume (VT) and minute volume (VE) in the different phases of the sleep-wake cycle. The groups of animals used for analysis of respiratory muscle activity were recorded for only 2 hours. CIH promoted significant alterations only in the duration of REM episodes. However, animals from CIH group had higher average levels of SBP (145,0 ± 1,8 vs 129,3 ± 2,2 mmHg), DBP (104,1 ± 1,7 vs 91,4 ± 1,8mmHg), MAP (121 ± 9 vs 107,7 ± 1,9 mmHg) e HR (387, ± 5,4 vs 363,5 ± 8,7 bpm) in the 3-hour recording period. These increases were also observed in all phases of the sleep-wake cycle. CIH also promoted a significant increase in VT during NREM (6,6 ± 0,2 vs 5,8 ± 0,2 mL/kg) and REM (6,4 ± 0,2 vs 5,3 ± 0,2 mL/kg), although this parameter was not significantly different during wakefulness in CIH animals compared to CTL animals. Both groups presented active expiration only during wakefulness, however it was much more frequent in HCI rats. In addition, in CIH animals, the fall in MAP (-18 ± 0,8 vs -14 ± 0,6 mmHg) and the increase in HR (28,4 ± 1,8 vs 21,8 ± 1,1 bpm) associated with DBs presented higher magnitudes in relation to CTL animals, although the time interval between DBs did not change. These findings indicate that CIH for 10 days promotes longer REM episodes, increased BP and HR in all phases of the cycle, increased VT during sleep, increased active expiration occurrence and higher magnitudes of the hemodynamic responses associated with DBs. Therefore, the cardiovascular alterations observed after CIH are due to the intermittent hypoxia episodes that occur throughout this protocol, but do not seem to be related to changes in the sleep-wake cycle, for although the duration of REM episodes was longer, the cardiovascular parameters were equally increased in all phases of the sleep-wake cycle.
33
Fuchs, Fanny. "Impact des conditions d'hébergement sur le vieillissement cognitif chez le rat : études comportementales, électrophysiologiques et neurochimiques." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ077/document.
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Cette thèse avait pour but d’étudier dans quelle mesure l’enrichissement des conditions d’hébergement jusqu’à- ou à partir d’-un âge auquel les déficits cognitifs sont déjà présents contribue au maintien de la mémoire spatiale observé chez des rats âgés hébergés toute leur vie en environnement enrichi (EE), et d’étudier certains mécanismes neurobiologiques susceptibles de contribuer à cette préservation. Nous avons montré que l’hébergement en EE n’a pas besoin d’être maintenu jusqu’à la fin de la vie pour permettre la préservation des fonctions cognitives chez le Rat âgé. De plus, un enrichissement tardif ne permet pas de récupérer des capacités déjà altérées mais permet la préservation de certaines fonctions d’altérations subséquentes. Ce maintien de la mémoire spatiale ne semble pas être dû à la modification par l’enrichissement du cycle veille-sommeil. Par contre, cet enrichissement induit une modification de l’activité oscillatoire hippocampique, et pourrait, en favorisant une synchronisation neuronale locale, promouvoir un traitement de l’information au sein de réseaux plus spécialisés. Enfin, l’exposition à un EE pendant toute la vie permet la préservation de l’innervation cholinergique de différentes aires cérébrales, un effet pouvant contribuer au maintien des fonctions cognitives chez les animaux âgés hébergés toute leur vie en EE<br>This thesis aimed to investigate in which extent environmental enrichment (EE) until or from an age at which cognitive decline is already apparent contributes to the maintenance of spatial memory observed in aged rats housed all their life in EE, and to study some neurobiological mechanisms likely underlying this preservation. We showed that housing in EE does not need to be maintained until the end of life to allow the preservation of cognitive function in aged rats. Moreover, late EE does not permit the recovery from already altered capabilities, but enables the preservation of some functions of subsequent alterations. The maintenance of spatial memory does not seem to be due to EE-related modification of sleep-wake cycle. But, exposure to EE induces a modification of hippocampal oscillatory activity, and could, by supporting local neuronal synchronization, promote information processing in more specialized networks. Finally, EE preserves the cholinergic system from age-related alteration in different cerebral areas, a mechanism that could participate to the maintenance of cognitive function in aged rats housed all their life in EE
34
Maia, Ana Paula Le?o. "Efeito do exerc?cio f?sico matinal realizado sob luz solar no ciclo vig?lia-sono de adolescentes." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17266.
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Previous issue date: 2008-06-04<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior<br>The sleep onset and offset delay at adolescence in relation to childhood. Besides biological causes, some external factors as academic obligations and socialization contributes, increasing
the burden of school and socialization. However, morning school schedules reduce sleep duration. Besides light strong effect, studies in humans have indicated that exercise influence circadian synchronization. To evaluate the effect of the morning exercise under sunlight on sleep-wake cycle (SWC) of adolescents, 160 high school students (11th
year) were exposed to the following conditions: lesson in usual classroom (Group C), lesson in swimming pool
exposed to sunlight (Group E), half of them carrying through physical activity (EE) and the other resting (EL). Each experimental group met two stages: assessment of SWC 1 week before and 1 week during the intervention, which was held in Monday and Wednesday between 7:45 and 8:30 am. In the baseline, there were applied the questionnaires "Health and Sleep" and cronotype evaluation (H & O). In addition, students were evaluated before and during the intervention by "Sleep Diary", "Karolinska Sleepiness Scale" (KSS), Psychomotor Vigilance Test (PVT) and actimetry. During the intervention, there was a delay in wake-up
time on the weekend and a trend to greater sleep duration on week for the three groups. At the weekend, only the groups EE and EL increased sleep duration. There was no difference in bedtime, irregularity of sleep schedules and nap variables. The sleepiness showed a circadian pattern characterized by higher alertness levels at 11:30 am and sleepiness levels at bedtime and wake-up time on week. On weekends there were higher levels of alertness in these times.
In the days of intervention, there was an increase of sleepiness at 11:30 am for groups EL and EE, which may have been caused by a relaxing effect of contact with the water of the pool. In addition, the group EE showed higher alert levels at 14:30 pm on Monday and at 8:30 am in the Wednesday, possibly caused by exercise arousal effect. The reaction time assessed through the TPV did not vary between the stages. The sleep quality improved in the three groups in the second stage, making impossible the evaluation of intervention effect. However, the sleep quality increased on Monday and Tuesday only on the group EE. From the results, it
is suggested that the intervention promoted effects on the sleepiness at some day hours. In other SWC variables there were no effects, possibly due to a large SWC irregularity on weekends. Thus, the evaluation of higher weekly frequency EF is necessary, since only two days were insufficient to promote greater effect on adolescents SWC<br>Na adolesc?ncia h? uma tend?ncia a dormir e acordar mais tarde em rela??o ? inf?ncia. Embora esta caracter?stica tenha causas biol?gicas, alguns fatores externos podem favorec?-la: como o aumento da carga escolar e da socializa??o. No sentido contr?rio os hor?rios
escolares matutinos representam um dos grandes fatores respons?veis pela priva??o parcial de sono. Ainda que a exposi??o ? luz seja considerada o regulador mais importante do sistema circadiano em mam?feros, estudos em seres humanos indicaram que o exerc?cio f?sico influencia a sincroniza??o circadiana. Por isso, o objetivo do nosso trabalho ? avaliar o efeito do exerc?cio f?sico matinal sob luz solar no ciclo vig?lia-sono (CVS) de adolescentes. O estudo contou com a participa??o de 160 alunos do ensino m?dio (1? e 2? ano), expostos ?s seguintes condi??es: aula na sala habitual (Grupo C), aula na piscina exposto ? luz solar
(Grupo E), metade em exerc?cio f?sico (EE) e outra em repouso (EL). Cada grupo experimental cumpriu duas etapas: avalia??o do CVS 1 semana antes e 1 semana durante a
interven??o, que foi realizada na 2? e 4? feira entre 7:45 e 8:30 h. Na linha de base foram aplicados os question?rios Sa?de e Sono e de avalia??o do cronotipo (H&O). Al?m disso, os alunos foram avaliados antes e durante a interven??o pelo Di?rio de sono , Escala de
Sonol?ncia de Karolinska (ESK), Teste de vigil?ncia psicomotora (TPV) e actimetria. Durante a interven??o, houve atraso no hor?rio de acordar no fim de semana e tend?ncia a maior dura??o do sono na semana nos tr?s grupos. No fim de semana, apenas os grupos EE e EL passaram a dormir mais. N?o houve diferen?a no hor?rio de dormir, na irregularidade dos hor?rios de sono e nas vari?veis do cochilo. A sonol?ncia apresentou um padr?o circadiano caracterizado por maior alerta ?s 11:30 h e maior sonol?ncia nos hor?rios de acordar e dormir na semana, e menor sonol?ncia nos finais de semana. Nos dias de interven??o, houve um
aumento da sonol?ncia ?s 11:30 h para os grupos EE e EL, que pode ter sido decorrente de um efeito relaxante do contato com a ?gua da piscina. Al?m disso, o grupo EE apresentou maiores
n?veis de alerta ?s 14:30 h na 2? feira e ?s 8:30 h na 4? feira, possivelmente decorrentes de um efeito ativacional do exerc?cio. O tempo de rea??o avaliado por meio do TPV n?o variou entre as etapas. A qualidade do sono melhorou nos tr?s grupos na 2? etapa, impossibilitando avaliar o efeito da interven??o. Entretanto, houve melhora na qualidade do sono na 2? e 3? feira apenas para o grupo EE. A partir dos resultados, sugere-se que a interven??o promoveu
efeitos sobre a sonol?ncia em alguns hor?rios. Nas outras vari?veis n?o foram observados efeitos, possivelmente devido a uma grande irregularidade no CVS nos finais de semana. Faz-
se necess?rio ampliar o estudo com a realiza??o de exerc?cio f?sico numa freq??ncia semanal maior, visto que apenas dois dias foram insuficientes para promover maiores efeitos no CVS
dos adolescentes
35
Aussel, Amélie. "Computational modeling of healthy and epileptic hippocampal oscillations." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0202.
Full textAbstract:
L'hippocampe peut présenter différents rythmes oscillatoires au cours du cycle veille-sommeil, chacun étant impliqué dans des processus cognitifs. Par exemple, des oscillations thêta-gamma sont produites pendant la veille et sont associés à la navigation spatiale et la mémoire à court terme, tandis que des complexes sharp-wave-ripples, produits durant les périodes de sommeil lent profond, jouent un rôle important dans la consolidation de la mémoire. Des modèles existent pour reproduire chacun de ces rythmes, cependant les mécanismes impliqués dans leur génération et les transitions entre eux ne sont pas encore parfaitement compris. Cette question est d'autant plus importante qu'une altération des rythmes hippocampiques est impliquée dans l'épilepsie du lobe temporal médian phamaco-résistante, une forme courante d'épilepsie qui ne peut pas être contrôlée par les traitements médicamenteux existants. Des modèles ont aussi été développés pour reproduire des crises d'épilepsie ou des pointes intercritiques, mais ces modèles ne parviennent pas à expliquer entièrement les liens entre les conditions neuropathologiques de l'hippocampe, des processus physiologiques comme le cycle veille-sommeil, et les oscillations qui en résultent. Dans ce contexte, l'objectif principal de cette thèse est d'apporter une meilleure compréhension de diverses oscillations hippocampiques, tant physiologiques que pathologiques. Pour ce faire, nous développons tout d'abord un modèle computationnel de l'hippocampe sain incluant au total plus de trente mille neurones Hodgkin-Huxley, représentés par des dizaines de milliers d'équations différentielles résolues numériquement, et comprenant une estimation du potentiel extracellulaire (LFP) généré par les neurones dipolaires tel que mesuré par une électrode macroscopique afin d'être plus facilement interprété. Nous effectuons ensuite une étude complète de l'activité de notre réseau basée sur des plans d'expérience afin d'étudier le rôle des paramètres intrinsèques du modèle et l'importance de la stimulation en entrée dans la production de différents rythmes couplés. Par la suite, notre modèle est évalué dans un contexte réaliste: l'activité qu'il génère quand il est soumis à des entrées réalistes est comparée avec des enregistrements intracérébraux obtenus sur des patients épileptiques. Nous montrons ainsi que notre modèle est capable de générer des oscillations de veille ou de sommeil similaires aux signaux cliniques sur le plan temporel et fréquentiel. Nous relions les modifications de paramètres du modèle (gains synaptiques et conductances de canaux ioniques) à une modulation cholinergique, et montrons comment les dynamiques des neurones influencent principalement les oscillations basse fréquence, tandis que la connectivité fonctionnelle contrôle les oscillations haute fréquence. Enfin, nous détaillons davantage notre modèle afin d'inclure quatre modifications de l'hippocampe observées dans les cas d'épilepsies du lobe temporal médian, à savoir la sclérose hippocampique, le bourgeonnement des fibres moussues, et une altération des dynamiques potassiques et chloriques (qui se traduisent par des modifications de la connectivité du réseau ou des paramètres des neurones individuels), et montrons comment ces mécanismes peuvent interagir avec le cycle veille-sommeil décrit précédemment pour donner lieu à des synchronisations et rythmes pathologiques. En conclusion, nous proposons dans cette thèse un modèle unique de l'hippocampe regroupant divers mécanismes précédemment décrits dans des travaux séparés, et analysons son activité oscillatoire tandis que nous varions différents paramètres représentant les propriétés structurelles et fonctionnelles du réseau, ainsi que des modifications pathologiques observées en épilepsie. Nos résultats apportent un nouvel éclairage sur les mécanismes impliqués dans la génération des oscillations hippocampiques, qui pourraient ouvrir la voie à de futures applications cliniques<br>The hippocampus can exhibit different oscillatory rhythms within the sleep-wake cycle, each of them being involved in cognitive processes. For example, theta-nested gamma oscillations, consisting of the coupling of theta and gamma rhythms, are produced during wakefulness and are associated with spatial navigation and working memory tasks, whereas sharp-wave-ripple complexes, consisting of fast oscillatory events occurring during low frequency waves, are produced during slow-wave sleep and quiet waking and play an important role in memory consolidation. Models exist to reproduce and explain the generation of each of these rhythms, yet the mechanisms involved in their generation and the transitions between them are not yet fully understood. This question is all the more important that altered hippocampal rhythms are involved in drug-resistant mesial temporal lobe epilepsy, a common form of epilepsy which cannot be controlled by existing pharmaceutical treatments. Some models have also been previously developed to reproduce epileptic seizures (episodes of excessive neural activity) or interictal discharges (brief peaks of synchronous activity), but these models cannot fully explain the links between neuropathological conditions of the hippocampus, physiological processes such as the sleep-wake cycle, and the resulting oscillations. In this context, the main objective of this thesis is to provide better understanding of various hippocampal oscillations, both physiological and pathological. To do so, we first design a full computational model of the healthy hippocampal formation including the entorhinal cortex, the dentate gyrus and the CA3 and CA1 regions. This model includes more than thirty thousand Hodgkin-Huxley point neurons, represented by tens of thousands differential equations to be solved numerically, as well as an estimation of the extracellular potentials (LFP) generated by the dipolar neurons as measured by a macroscopic electrode, so as to be more easily interpretable. We perform a thorough study of our model's activity based on design of experiments techniques to identify the role of each of its intrinsic parameters and the importance of input stimulation in the production coupled oscillatory outputs. We then evaluate our model in a realistic context : its activity under realistic input stimulation is compared with intracranial recordings obtained in epileptic patients. We demonstrate that our model is able to reproduce both sleep and wakefulness oscillations with temporal and frequential similarities with the clinically measured signals. We link the modification of some parameters of the model (synaptic gains and ion channel conductances) with cholinergic modulation, and show how single neuron dynamics are mostly responsible for the frequency of slow oscillations of our network, while network functional connectivity controls its fast oscillations. Finally, we detail our model further to include four pathological modifications of the hippocampus seen in mesial temporal lobe epilepsies, that is hippocampal sclerosis, mossy fiber sprouting, and impaired potassium and chloride dynamics in pyramidal neurons (which are modeled by changing the network connectivity or the parameters of individual neuron dynamics), and show how these mechanisms can interact with the previously described sleep-wake cycle and lead to pathological synchrony and rhythms such as seizures, interictal spikes and fast ripples. In conclusion, we propose in this thesis a unique model of the hippocampus regrouping many mechanisms previously described in separate works, and analyze its oscillatory activity as we vary different parameters representing either structural or functional properties of the network, as well as pathological modifications observed in epilepsy. Our results provide new insights into the mechanisms underlying the generation of various hippocampal oscillations, which could open the way to future clinical applications
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Cabanas, Magali. "Modification des activités de réseaux in vivo chez un modèle murin de la maladie de Huntington." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0345/document.
Full textAbstract:
La maladie de Huntington est une pathologie héréditaire qui se caractérise par une dégénérescence sélective des neurones striataux de la voie indirecte des ganglions de la base. Chez les patients ainsi que chez les souris modèles de la pathologie, en plus des symptômes moteurs, cognitifs et psychiatriques, des troubles du sommeil peuvent aussi apparaitre dès la phase pré-symptomatique. L’étude électrophysiologique in vivo des souris transgéniques R6/1a, en outre, révélé en début de phase symptomatique l’apparition du rythme pathologique β observé principalement durant le sommeil. Ces travaux de thèses ont donc eut pour but d’étudier le lien entre les modifications d’activités de réseaux cérébraux, les troubles du sommeil et l’émergence du rythme β ainsi que l’implication de ces anomalies dans les perturbations comportementales observées chez les souris R6/1. Notre étude de l’imagerie c-Fos a montré une hyperactivation de la voie frontostriatale chez ces souris, et ceci uniquement au stade pré-symptomatique sans aucune modification d’activation de la voie indirecte. Notre étude pharmacogénétique a démontré que la modification d’activité de ces neurones de projection striataux pouvait modifier l’alternance veille/sommeil mais ne pouvaient générer le rythme β. Enfin, notre étude pharmacologique a établit le lien entre le dysfonctionnement du système orexinergique et l’émergence du rythme β chez les souris R6/1. Ces travaux ont permis de mieux décrire des modifications d’activités de réseaux associées aux différents stades de la pathologie, en particulier au stade présymptomatique, et leurs contributions aux troubles du sommeil et l’émergence du rythme β<br>Huntington’s disease (HD) is an inherited pathology that causes selective degeneration ofindirect striatal pathway neurons of the basal ganglia. In addition to the classic motor,cognitive and psychiatric symptoms, patients and mouse models of HD develop sleepdisorders, which can appear at as early as pre-symptomatic stage. Furthermore, in vivoelectrophysiological study of R6/1 transgenic mice revealed a unique and pathological βrhythm that appear at early symptomatic stage and which is mainly observed during sleep.The aim of this thesis work was to examine the link between changes in cerebral networkactivities, sleep disturbances and β rhythm, and to determine the contribution of theseabnormalities to the behavioral disturbances observed in R6/1 mice. Our neuroimaging study of the marker of neuronal activity c-Fos showed a hyperactivation of frontostriatal pathway at pre-symptomatic stage without any activity changes of the vulnerable indirect pathway neurons. Our pharmacogenetic study demonstrated that changes of striatal projection neuronal activity can modify sleep/wake behaviors, without inducing the pathological β rhythm. Finally, our pharmacological study established a link between orexinergic system dysfunction and β rhythm emergence in R6/1 mice. Our data, therefore, described further the natures of altered neural circuit activity associated with different disease stages, in particular pre-motor symptomatic period, and the importance of these alterations for sleep disturbances as well as β rhythm appearance in transgenic HD mice
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Clodore, Martine. "La vigilance : evolution circadienne et horaires de sommeil, importance de la typologie matin/soir." Paris 6, 1988. http://www.theses.fr/1988PA066153.
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Ribeiro, Jo?o Miguel Gon?alves. "Caracteriza??o do perfil do ciclo sono-vig?lia em ratos sob dessincroniza??o for?ada." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18487.
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Previous issue date: 2011-12-08<br>Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico<br>The circadian behavior associated with the 24 hours light-dark (LD) cycle (T24) is due to
a circadian clock , which in mammals is located in the hypothalamic suprachiasmatic
nucleus (SCN). Under experimental conditions in which rats are espoused to a
symmetric LD 22h cycle (T22) the two SCN regions, ventrolateral (vl) and dorsomedial
(dm), can be functionally isolated, suggesting that each region regulates distinct
physiological and behavioral components. The vl region regulates the locomotor activity
and slow wave sleep (SWS) rhythms, while the dm region assures the body
temperature and paradoxical sleep (PS) rhythms regulation. This research aimed to
deepen the knowledge on the functional properties of circadian rhythmicity, specifically
about the internal desynchronization process, and its consequences to locomotor
activity and body temperature rhythms as well as to the sleep-wake cycle pattern in
rats. We applied infrared motion sensors, implanted body temperature sensors and a
telemetry system to record electrocorticogram (ECoG) and electromyogram (EMG) in
two rat groups. The control group under 24h period LD cycle (T24: 12hL-12hD) to the
baseline record and the experimental group under 22h period LD cycle (T22: 11hL-
11hD), in which is known to occur the uncoupling process of the circadian locomotor
activity rhythm where the animals show two distinct locomotor activity rhythms: one
synchronized to the external LD cycle, and another expressed in free running course,
with period greater than 24h. As a result of 22h cycles, characteristic locomotor activity moment appear, that are coincidence moments (T22C) and non coincidence moments
(T22NC) which were the main focus or our study. Our results show an increase in
locomotor activity, especially in coincidence moments, and the inversion of locomotor
activity, body temperature, and sleep-wake cycle patterns in non coincidence
moments. We can also observe the increase in SWS and decrease in PS, both in
coincidence and non coincidence moments. Probably the increases in locomotor
activity as a way to promote the coupling between circadian oscillators generate an
increased homeostatic pressure and thus increase SWS, promoting the decreasing in
PS<br>O comportamento circadiano associado ao ciclo di?rio de 24 horas deve-se ? a??o de
um rel?gio circadiano que em mam?feros se localiza nos n?cleos supraquiasm?ticos
do hipot?lamo (NSQs). Sob condi??es experimentais em que ratos s?o submetidos a
um ciclo claro-escuro (CE) sim?trico de 22h (T22) as regi?es ventrolateral (vl) e
dorsomedial (dm) dos NSQs podem ser separadas funcionalmente, sugerindo que
cada regi?o regula vari?veis fisiol?gicas distintas. A regi?o vl regula os ritmos de
atividade e sono de ondas lentas (SOL), enquanto a regi?o dm ? respons?vel pelo ritmo
da temperatura corporal e sono paradoxal (SP). A investiga??o desenvolvida no
presente trabalho visou aprofundar o conhecimento sobre as propriedades funcionais
da ritmicidade circadiana, mais especificamente sobre o processo da
dessincroniza??o interna e as suas implica??es no ritmo de atividade locomotora,
temperatura corporal e padr?o do ciclo sono-vig?lia em ratos. Com este objetivo, foram
utilizados sensores de movimentos por infravermelho e implantados sensores para
temperatura corporal, al?m disso o sistema de telemetria foi utilizado para o registro de
par?metros fisiol?gicos de eletrocorticograma (ECoG) e eletromiograma (EMG), em
dois grupos de animais. O grupo controle sob ciclo claro-escuro com per?odo de T24
(12h claro: 12h escuro), para o registro basal das vari?veis em an?lise; e o grupo
experimental sob ciclo claro-escuro com per?odo de T22 (11h claro: 11h escuro), no
qual se sabe que ocorre o desacoplamento do ritmo circadiano de atividade locomotora e os animais apresentam dois componentes distintos de atividade: um
sincronizado ao ciclo claro-escuro; e outro que se expressa em livre curso, com
per?odo maior que 24h. Em decorr?ncia do protocolo de dessincroniza??o for?ada,
surgem momentos caracter?sticos no perfil de atividade locomotora: momentos de
coincid?ncia (T22C) e de n?o coincid?ncia (T22NC), que foram o foco principal do
nosso estudo. Podemos observar o aumento de atividade locomotora principalmente
em momentos de coincid?ncia, e a invers?o do padr?o de atividade locomotora,
temperatura corporal e ciclo sono-vig?lia em momentos de n?o coincid?ncia. Podemos
ainda observar o aumento do SOL e diminui??o do SP, tanto em momentos de
coincid?ncia como em momentos de n?o coincid?ncia. ? prov?vel que o aumento da
atividade locomotora como forma de facilitar o acoplamento entre os osciladores
circadianos gere um aumento da press?o homeost?tica e com isso aumento de SOL, e
diminui a dura??o de SP
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Nguyen, John Loc. "The effects of reversing sleep-wake cycles on sleep and fatigue on the crew of USS John C. Stennis." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FNguyen.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2002.<br>Thesis advisor(s): Nita L. Miller, Samuel E. Buttrey, Susan M. Sanchez. Includes bibliographical references (p. 147-149). Also available online.
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Tosun, Pinar Deniz. "Analysis of brain activity during the sleep-wake cycles of rodents and humans with symbolic dynamic analysis of the electroencephalogram." Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/846155/.
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Sleep is an essential physiological phenomenon which is regulated by fundamental sleep-wake cycles. Sleep is formed of non-rapid-eye-movement (NREM) and REM stages where NREM and REM sleep stages alternate with wakefulness in a whole night sleep (i.e., typically consists of several sleep-wake cycles). During sleep, brain is active and the activity also alters with changing vigilance states (VS). Furthermore, physiological or external changes in the brain structure might influence brain activity during sleep. Effects of ageing, sex differences, and pharmacological manipulations have been widely investigated in sleep research using Fourier Transform. However, the use of non-linear analysis techniques might be more suitable in analysing non-linear and non-stationary signals (e.g., electroencephalogram (EEG)). Therefore, non-linear analysis has been used within this PhD with the hypothesis that these methods might reveal hidden characteristics in the changing brain signals that are difficult to detect with traditional EEG power spectral density analysis. The use of non-linear analysis techniques (e.g., symbolic dynamic analysis (SDA)) will allow to further dissect the physiological significance of activity-dependent changes of neuronal networks across sleep-wake cycles, as well as the significance of brain activity patterns during waking, sleep, sleep deprivation (SD), or induced by sleep-promoting drugs and pharmacological treatments. In this PhD, rodent and human sleep EEG recordings were analysed using SDA methods: Lempel-Ziv complexity (LZC), Permutation Entropy (PE) and Permutation Lempel-Ziv complexity (PLZC). All the methods were able characterise different VS with wakefulness and REM sleep resulting in higher measures of complexity compared to NREM sleep suggesting an active state of the brain in these VS. This was measured in all datasets assisting the hypothesis on the usefulness of these techniques in sleep research by providing the minimum requirement for sleep analysis. In addition to this, SD significantly reduced complexity in the following sleep period supporting the compensation process for the lost sleep by the increased in slow wave activity which was reflected as reduced complexity in this study. Furthermore, a low dose tiagabine administration’s sleep compensation promoting effect was found in mice. Moreover, ageing was identified as a main effect on changes in brain activity. These changes were more pronounced in the old age where complexity was significantly lower compared to young age. On the one hand, this was found with all three methods and contributing to the hypothesis that these techniques reveal structural dynamic changes due to physiological alterations. On the other hand, no significant differences in complexity across genders were found suggesting the underlying mechanisms to maintain sleep-wake cycles are similar for men and women. This finding with further investigation might corroborate to question the need to use both genders in drug trials. Furthermore, significant changes in brain activity were found at different times of the sleep period highlighting the changes occurring within VS as sleep progresses. This also has an impact on the way sleep stages are scored and investigated which are influenced by different brain activity levels within each VS throughout the entire sleep. All in all, this study achieved to support its hypothesis of determining the changes in brain activity as a complexity measure by characterising sleep under physiological and pharmacologically induced EEG datasets in mice and in humans. The study was a novel application to analyse sleep in these conditions. However, with further analysis performed on larger datasets, its findings together with surrogate data analysis proved SDA techniques’ robust usability which can complement the gold standard FT analysis in sleep research.
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Singletary, Kristan Gail. "Nocturnal bird migration and disrupted sleep/wake cycle." 2009. http://hdl.handle.net/2152/6637.
Full textAbstract:
In most birds, changing photoperiods from winter to spring and from summer to
fall have two consequences: increased feeding followed by migratory activity. To date,
the neural system controlling the activation of migratory activity remains unknown,
though behavioral observations point to a possible mechanism. During the migration
season, diurnal songbirds show extensive disruption of their sleep/wake cycle, sleeping
during the day and flying at night. In mammals, similarly altered cycles of activity result
from blocking orexin expression in the hypothalamus. It is possible that decreased orexin
expression is associated with migratory activity in songbirds. In addition, changes in
ingestive behaviors and fuel availability may also be associated with disruptions in the
sleep/wake cycles of migratory birds. The studies in my dissertation will address these
issues through three main specific aims. First, I will determine that orexin systems are
conserved in vertebrate brains. Second, I will test the association between orexin and
migratory activity in songbirds. Third, I will confirm the association between fuel
availability, orexin expression and migratory activity in songbirds.<br>text
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Evans, Barbara Duffy. "Wrist-actigraphic assessment of 24 hour sleep-wake patterns in the community elderly a research project submitted in partial fulfillment ... Master of Science (Gerontological Nursing) /." 1990. http://catalog.hathitrust.org/api/volumes/oclc/68795153.html.
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Mir, Saba. "Noradrenergic modulation of airway-related muscle activity across the sleep-wake cycle." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=450436&T=F.
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Wang, Yi-Ping, and 王奕評. "Effects of Sleep-wake Cycle and Circadian Rhythm on Blood Pressure Dipping in Rats." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/48338091244556072846.
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碩士<br>國立陽明大學<br>腦科學研究所<br>99<br>Background: 24 h ambulatory blood pressure (BP) monitoring present BP dipping pattern during sleep in healthy subject. The extent of the BP decline is highly correlation with target organ damage (TOD) and cardiovascular disease. Circadian rhythm and sleep-wake cycle are the two factors causing BP dipping. Autonomic nervous system plays a major role in BP regulation and sleep cycle change. Aims: Building a BP dipping animal model, which is useful for studying the mechanism of BP dipping. Hypothesis: We hypothesis that Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) would have BP dipping and non-dipping pattern. We aim to investigate effects of circadian rhythm and sleep-wake cycle on BP dipping in rats. Finally, we attempt to find the possible reason which causes dipping and non-dipping pattern in BP. Materials and Methods: 10-11 week-old WKY and SHR were used. One week after the electrode and telemetry transmitter implantation, blood pressure, electroencephalogram, electromyogram and electrocardiogram were continuously recorded for 24 hours in freely moving rats. Sleep-wake stage was defined using electroencephalogram electromyogram power spectrum, as active waking (AW), quiet sleep (QS), paradoxical sleep (PS). BP dipping was defined as the BP difference between light phase QS and dark phase AW. Rats were divided into dippers and non-dippers according to the amount of BP difference (>10% or &lt;10% decline). BP and autonomic function were compared between two groups. Comparisons between two groups were tested by independent t test, and relationships between two sets of variables were measured by the linear regression analysis. Results: We found that rats have diurnal rhythm in BP like human. The effect of sleep-wake change caused BP dipping in rats. Compared with dippers, RR interval increase was not found during light period in non-dippers. In addition, QS LF% during light period was correlated with the amount of BP difference in WKY. Conclusion: We establish an animal model for BP dipping in rats. The possible mechanism of dipping pattern is sleep-wake change. However, abnormal circadian rhythm would cause non-dipping pattern in rats. Higher QS cardiac sympathetic activity during light period is a risk factor of non-dipping pattern.
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Lee, Pei-ying, and 李佩穎. "The Effects of Light/dark Cycle Change on Sleep/wake Related Cardiac Autonomic Functions in Rats." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/24804956425652300375.
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碩士<br>慈濟大學<br>神經科學研究所<br>94<br>Many evidences had provided important links among circadian rhythm disorder and/or sleep disorder and essential hypertension. However, the interactions between circadian rhythm and sleep stages on cardiac autonomic functions remain unclear. This study was designed to investigate the autonomic differences of sleep stages between light and dark period in spontaneously hypertensive (SHR) and Wistar-Kyoto rats (WKY), and whether there were any differences between SHR and WKY throughout a day. All WKY and SHR had electrodes implanted for polygraphic recordings. One week later, a 24-hour sleep-wakefulness recording session was analyzed. Twenty-four hours of electroencephalogram (EEG), electromyogram and electrocardiogram were recorded in freely moving rats throughout a 24-h diurnal cycle, consisting of a 12-h light and a 12-h dark period. Frequency-domain analysis of the stationary R-R intervals (RR) was performed to quantify the total power (TP), the high-frequency power (HF), and the low-frequency power (LF)-to-HF ratio (LF/HF) of heart rate variability. Differences among active waking (AW), quiet sleep (QS), and paradoxical sleep (PS) stages between light and dark periods of the day were compared. As compared with WKY, the accumulated time of SHR was longer at AW stage and shorter at QS stage in light period and the accumulated time of SHR was shorter at AW stage and longer at PS stage in dark period. The d-power percentage of EEG during QS stage was significantly lower in SHR in light period but was similar with WKY in dark period. Similar with WKY, the RR and TP during AW stage, and HF during each stage were significantly lower in the dark period than those in the light period in SHR. The HF in SHR was significantly lower than those in WKY during each stage and each period. The LF/HF during QS stage was significantly higher in SHR than those in WKY both the light and dark period. Shifting the light-dark cycle by 4 h resulted in immediate significant changes in sleep pattern and heart rate variability. There was a gradual shift in sleep pattern to a new rhythm that appeared to stabilize from shift day 5, and R-R interval values were shifted in a new rhythm by day 4. These results indicate that both rat strains had decreased cardiac vagal activity but increased sympathetic modulation during sleep in dark period than that in light period. SHR has a more interrupted sleep and elevated sympathetic activity both during light and dark periods as compared to WKY. These differences of sleep and related autonomic functions in SHR may play an important role in the developing of hypertension.
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Hagar, Kristine Ann. "The effect of physical activity on sleep in children with autism." 2005. http://www.oregonpdf.org.
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Bernert, Rebecca A. "A circadian vulnerability for depression eveningness and sleep variability /." Diss., 2005. http://etd.lib.fsu.edu/theses/available/etd-11142005-112652.
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Thesis (M.S.)--Florida State University, 2005.<br>Advisor: James Joiner, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Feb.1, 2006). Document formatted into pages; contains vi, 23 pages. Includes bibliographical references.
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Roach, Gregory D. "Circadian disruption and adaptation associated with night work and transmeridian flight." 2001. http://arrow.unisa.edu.au:8081/1959.8/24974.
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Shiftwork, particularly that involving night work and/or transmeridian flight, forces a mismatch between the sleep/wake cycle and the endogenous circadian timing system. Specifically, shiftworkers are often required to sleep at a phase in the circadian cycle when they would usually be active, and to work at a phase in the circadian cycle when they would usually be asleep. The current thesis describes a series of five studies designed to examine the disruption and adaptation associated with shiftwork, with an emphasis on night work and, to a lesser extent, transmeridian flight. The first study (Chapter 3), conducted in the field, was designed to examine the effects of break duration and time of break onset on the amount of sleep that shiftworkers obtain between consecutive work periods, and to consider the role that pineal production of melatonin may play in this process, through its regulation of sleep. Not surprisingly, total sleep time (TST) increased with break duration for breaks that began at similar times of day. Importantly though, TST was greater for breaks that occurred during the night-time than for breaks that occurred during the daytime. These results indicated that the minimum-length break requirements contained in prescriptive duty hours regulations might not necessarily protect shiftworkers from being exposed to unacceptable levels of fatigue. In addition, there was a temporal relationship between the circadian rhythms of sleep duration, sleep quality, and 6-sulphatoxymelatonin excretion, such that sleep was longer and of better quality when melatonin production was relatively high. This data did not prove a causal link, but it did provide further indication that melatonin may be involved in the regulation of sleep. The aim of the second study (Chapter 4) was to examine the effects of time of day, shift duration, and prior sleep length on self-assessed alertness and neurobehavioural performance of shiftworkers in a real work setting. Cosinor regression models fitted to the data indicated that time of day had a significant effect on alertness and performance, with both reaching nadirs in the early morning. Indeed, the cosinor regression lines of best fit explained more than 90% of the within-subjects variability in both the alertness and performance measures. In addition, alertness declined as shift duration increased and rose as prior sleep length increased, and there was a decline in performance across work periods that was greater for extended shifts. However, the results indicated that time of day was the most important determinant of subjective alertness and neurobehavioural performance. Consequently, the fatigue associated with night work can never be eliminated, only minimised through the application of risk management strategies. The aim of the third study (Chapter 5) was to quantify the effects of fatigue on performance in a simulated work environment, i.e. a rail simulator, and to compare them with the effects of alcohol intoxication. Reaction time (RT) performance on a visual psychomotor vigilance task (PVT) was also assessed. Rather than cause a general decline in performance as was hypothesised, fatigue impaired some safety and efficiency measures (i.e. number and duration of extreme speed violations increased, average speed reduced, brake use increased), but not others (i.e. fuel use, inter-train forces, and minor and moderate speed violations were unaffected). The reduction in safety and consequent increase in risk due to fatigue reached levels equivalent to those associated with moderate levels of alcohol intoxication (i.e. -05?-10%). The results indicated that fatigue caused participants to disengage from operating the simulator such that safety was traded off, not necessarily deliberately, against some aspects of efficiency. RT performance on the PVT was also significantly impaired by fatigue, similar to the magnitude of impairment associated with moderate levels of alcohol intoxication (i.e. -05?-10%). However, the PVT results could not predict the complex relationship between simulator safety and efficiency measures. This indicated that the effects of fatigue on performance in the workplace cannot necessarily be derived on the basis of simple performance measures such as RT. The fourth study (Chapter 6), conducted in the laboratory, was designed to assess adaptation to a simulated night work schedule using salivary dim light melatonin onset (DLMO) as the circadian phase marker. Participants worked seven consecutive simulated 8-hour night shifts (i.e. 23:00?07:00h). This resulted in a mean total phase delay in DLMO of 5.5 hours, equivalent to an average delay of 0.8 hours per day. In addition, baseline DLMO was significantly correlated with mean wake time over the previous seven days. These results indicated that partial circadian adaptation occurred in response to the simulated night work schedule, and that baseline DLMO was reliably predicted by the mean wake up time for the preceding week. The radioimmunoassay used proved to be a sensitive measure of melatonin concentration in saliva for the determination of DLMO, and thus provides an alternative phase marker to core body temperature. The last study (Chapter 7) was designed to examine the adaptation of a RAAF aircrew to several small time zone transitions using salivary melatonin onset as the marker of circadian phase. In addition, the effects of the aircrew?s work schedule on their sleep/wake patterns and subjective alertness were assessed. During the first six days of a routine surveillance patrol (SURPAT), the aircrew travelled eastward and melatonin onset occurred progressively earlier (i.e. phase advanced). During the second six days of the SURPAT, the aircrew travelled westward but melatonin onset did not significantly shift. Night-time sleep duration was shorter prior to work days than prior to rest days, and subjective alertness was not significantly affected by either the duration of night-time sleep prior to work, or the duration of flight. The melatonin onset results indicated that participants? body clocks adapted well to several small time zone transitions when initially travelling eastward, but did not adapt to a similar pattern of time zone transitions when subsequently travelling westward. This was contrary to expectations based on studies of single acute time zone transitions, which indicate that adaptation to westward flight is more rapid than adaptation to eastward flight. Taken together, the results of these five studies confirm that shiftwork provides a considerable source of disruption to shiftworkers? sleep/wake patterns. Whilst this disruption to shiftworkers? sleep may impair subjective alertness, the greatest influence on alertness and performance is exerted by time of day. Furthermore, the combined effects of sleep disruption and time of day may result in a level of performance impairment in a simulated work environment similar to that associated with moderate levels of alcohol intoxication. Finally, night work and transmeridian flight provide a source of circadian disruption, the adaptation to which can be assessed in both laboratory and field settings by examining changes in the timing of nocturnal melatonin onset.<br>thesis (PhD)--University of South Australia, 2001.
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Dostie, Valérie. "Impact de l’âge sur les effets de la caféine sur la vigilance chez les sujets jeunes et d’âge moyen." Thèse, 2012. http://hdl.handle.net/1866/8514.
Full textAbstract:
La grande disponibilité et les propriétés psychostimulantes de la caféine en font l’un des psychostimulants les plus consommés mondialement. Sa capacité à augmenter la vigilance serait reliée à son action antagoniste des récepteurs adénosinergiques. Le vieillissement s'accompagne de changements dans les mécanismes de régulation de la vigilance, y compris le système adénosinergique, qui pourraient moduler les effets de la caféine. Alors que plusieurs études ont investigué les impacts de la caféine sur la vigilance chez une population jeune, peu ont identifié les effets chez une population plus âgée. Deux protocoles expérimentaux pouvant distinguer les effets différentiels de la caféine selon l’âge ont été élaborés.
La première étude a évalué les effets de 200 mg de caféine sur la vigilance, comparée à un placebo, chez une population jeune et d’âge moyen lors d’une privation de sommeil de 25 heures. L’augmentation de la vigilance subjective et de la performance psychomotrice suite à l’administration de caféine est comparable dans les deux groupes d’âge. Or, des modifications de la puissance spectrale de certaines bandes de fréquences de l’EEG d’éveil suite à l’administration de la caféine sont spécifiques au groupe d’âge moyen.
Une deuxième étude a évalué les effets de 200 mg de caféine sur la vigilance, comparée à un placebo, chez des sujets jeunes et d’âge moyen consommateurs légers de caféine. La caféine n’a pas augmenté la vigilance subjective des consommateurs légers. Par ailleurs, la caféine a augmenté la performance psychomotrice de façon similaire dans les deux groupes d’âge. De plus, on remarque que la caféine induit des modifications de la puissance spectrale sur certaines bandes de fréquences à l’EEG chez le groupe d’âge moyen uniquement.
Ces travaux suggèrent tout d’abord que la caféine tend à augmenter la vigilance, peu importe le niveau basal d’alerte. De plus, malgré l’absence d’effet subjectif de la caféine sur la vigilance, les consommateurs légers de caféine montrent des effets sur les mesures objectives de la vigilance. Bien que la caféine augmente la vigilance chez les deux groupes d’âge, la spécificité de certaines modifications relevées à l’EEG suggère une augmentation de la sensibilité à la caféine selon l’âge. Il est possible qu’il existe des changements du système adénosinergique au cours du vieillissement qui sous-tendent les effets différentiels de la caféine au cours du vieillissement.<br>The availability and psychoactive properties of caffeine make it one of the most widely consumed behaviourally active substances in the world. The capacity of caffeine to increase vigilance relies on its antagonist action on adenosine receptors. Aging is associated with changes in the mechanisms regulating vigilance, possibly through changes in the adenosinergic system which could in turn affect eh influence of caffeine. While extensive research identified the impacts of caffeine on vigilance in young populations, few studies have investigated the effects in an older population. Two experimental protocols which can highlight the differential effects of caffeine according to age were elaborated.
The first study estimated the effects of 200 mg of caffeine on vigilance, compared with a placebo, in young and middle-aged subjects during 25 hours of sleep deprivation. Caffeine increased subjective and psychomotor measures similarly in young and middle-aged subjects. However, modifications of the spectral power in some frequencies bands after caffeine ingestion were specific to the middle-aged group.
The second study focused on the effects of 200 mg of caffeine on vigilance, compared with a placebo, in young and middle-aged light caffeine consumers. Caffeine did not increase subjective alertness in light consumers but enhanced psychomotor performance similarly in both age groups. Furthermore, caffeine affected waking EEG spectral power in specific frequencies bands in the middle-aged group only.
In conclusion, these results suggest that caffeine enhance vigilance when basal level of alertness is either high or low. Furthermore, light consumers show effects of caffeine on subjective vigilance but not on objective measures. In spite of an increase of alertness in both age groups, some modifications found in the waking EEG of middle-aged subjects suggest a differential effect of caffeine depending on age. It is possible to hypothesize that changes in the adenosinergic system occur during aging and these changes could explain our results.
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Becker, Ann. "Environmental impact on infant's developing melatonin levels and sleep -wake cycles." 2001. https://scholarworks.umass.edu/dissertations/AAI3012112.
Full textAbstract:
The purpose of the study is to describe the development of infant melatonin levels form birth to six months, and to examine the effects of seasonal luminosity, and nutrition on the development of melatonin levels and changes in circadian sleep:wake cycles. Additionally the study will investigate the role of infant, maternal and care giving variables on the development of infant sleep. This longitudinal study will be conducted in Tromso, Norway, which, because of its far northern location (70° North), provides extremes in seasonal variations and light/dark cycles. For two months in the Winter the sun never rises above the horizon and for two months in the Summer it never sets below the horizon. A total of 146 infants (ranging in age from birth to 6 months) and 146 mothers participated in the study. Four sampling periods occurred within a two week interval surrounding the Summer and Winter solstices and the Spring and All equinoxes. Results show that age is the primary developmental influence and seasonal light influences actual levels of development at three and six months of age.