Dissertations / Theses on the topic 'Contralateral and ipsilateral projections'

Because the precise alignment between contralateral and ipsilateral visual circuits is important for the development of visual system, both circuits need to be precisely regulated concurrently. Eph-ephrin and Teneurin are two protein families that may have important roles in regulating the development of the visual pathway (Kania & Klein, 2016; Leamey & Sawatari, 2014). However, while the roles of Eph-ephrin in the development of contralateral projection have been widely studied (Kania & Klein, 2016), the numbers of studies that have focused on ipsilateral projection is relatively low. On the other hand, while the roles of teneurins in ipsilateral projection have been reported, their roles in the formation of contralateral projections are less well-known. Glendining et al (2017) recently showed that there is a potential interaction between Ten-m3 and EphA7 as the expression of EphA7 was reduced in Teneurin transmembrane protein 3 (Ten-m3) KO (Glendining et al., 2017). This thesis will investigate the roles of Ten-m3 and EphA7 in regulating the development of ipsilateral and contralateral projections during the formation of topographic map in visual system respectively. The results point to complementary roles for Ten-m3 and EphA7 in regulating the development of ipsilateral projections in the visual system. However, similar topographic errors were found in the patterning of contralateral projections in the visual system in Ten-m3 KO and EphA7 KO. This suggest that Ten-m3 and EphA7 may have different roles during the development of ipsilateral and contralateral projections. Behavioural studies revealed a potential deficit in the ability of EphA7 KO mice to discriminate between visual stimuli located in their dorsal visual field, suggesting the functional importance of EphA7 in visual behaviors.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.
Includes bibliographical references (leaves 41-45).
by Watjana Lilaonitkul.
S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.
Includes bibliographical references.
A variety of evidence indicates that the brain controls the gain of mechanical amplification in the cochlea in a frequency specific manner through the medial olivocochlear (MOC) efferent pathway, but the degree of MOC frequency specificity in humans is poorly understood. This thesis investigates the tuning properties of the human MOC acoustic reflex at different cochlear frequency regions and with different MOC-elicitor lateralities and frequency contents. Effects produced by the MOC reflex were quantified by the magnitude of the induced changes in stimulus frequency otoacoustic emissions (deltaSFOAEs) at probe frequencies of 0.5, 1 and 4 kHz. With MOC activity elicited by a mid-level (60 dB SPL) tone or half-octave-band of noise, significant MOC-induced deltaSFOAEs were seen over a wide range of elicitor frequencies, e.g. for elicitor frequencies at least 11/2 octaves away from each probe frequency. deltaSFOAE-versus-elicitor-frequency patterns were sometimes skewed so that elicitors at frequencies above (0.5 kHz probe) or below (1 kHz probe) the probe frequency were most effective. In contrast to the wide frequency range of MOC effects from mid-level elicitors, for 1 kHz probes MOC-effect tuning curves (TCs) were narrow with Ql0s of -2, sharper than the MOC-fiber TCs with best frequencies near I kHz in cats and guinea pigs. When MOC effects were looked at as the MOC-inhibited SFOAE relative to the original SFOAE, the SFOAE magnitude decreases and phase changes appeared to be separate functions of elicitor frequency: SFOAE magnitude inhibition was largest for on-frequency elicitors (elicitor frequencies near the probe frequency) while MOC-induced SFOAE phase leads were largest for off-frequency elicitors.
(cont) One hypothesis to account for this is that on-frequency elicitors predominantly inhibit the traveling wave from the probe-tone, whereas off-frequency elicitors shift it along the frequency axis by selectively inhibiting apical or basal parts of the traveling-wave. These results are consistent with an anti-masking role of MOC efferents and suggest that MOC efferents do more than just provide feedback to a narrow frequency region around the elicitor frequency.
by Watjana Lilaonitkul.
Ph.D.

El presente trabajo se realizó con el propósito de evaluar el efecto de la transferencia embrionaria ipsilateral y contralateral a la posición del cuerpo lúteo sobre la tasa de preñez en llamas. Se utilizaron 43 llamas hembras receptoras de 4 a 6 años, distribuidas aleatoriamente en 4 grupos de estudio: G1 (n=10): Cuerpo lúteo en ovario derecho y transferencia ipsilateral, G2 (n=10): Cuerpo lúteo en ovario derecho y transferencia contralateral, G3 (n=15): Cuerpo lúteo en ovario izquierdo y transferencia ipsilateral y G4 (n=8): Cuerpo lúteo en ovario izquierdo y transferencia contralateral. Se utilizaron 10 llamas hembras como donadoras de embriones, las cuales fueron sincronizadas con LH (1ml), superovuladas con 1000 UI de eCG y se provocó luteólisis con prostaglandina (1ml), siendo empadradas posteriormente. El día del empadre las llamas receptoras recibieron tratamiento con LH, con el propósito de sincronizarlas con las donadoras. Siete días post empadre se realizó el lavado uterino para la recolección, evaluación y transferencia de los embriones. La transferencia embrionaria a los grupos experimentales se realizó con embriones frescos el mismo día. Los resultados obtenidos señalan una tasa de preñez de 60% (G1) y 75% (G3) en las hembras con transferencia embrionaria ipsilateral derecha e izquierda respectivamente, mientras que en la transferencia contralateral derecha e izquierda fueron 30% (G2) y 25%(G4) respectivamente. Sin embargo, no se registraron diferencias significativas (p>0.05) entre el grupo G1 con los grupos G2, G3 y G4, además G2 no muestra diferencias significativas (p>0.05) con G4. Mientras que se encontró diferencia (p menor 0.05) entre el grupo G3 con los grupos G2 y G4. Estos resultados indicarían una mayor tasa de sobrevivencia embrionaria en llamas al realizar la transferencia en el cuerno ipsilateral a la posición del cuerpo lúteo ubicado en el ovario izquierdo.
The study was carried out with the objective of to evaluate the embryo survival after the embryo transfer to the uterine horn ipsilateral and contralateral to the corpus luteum (CL) in llamas. Fourtythree llamas recipient females, from 4 to 6 years old were randomly assigned in 4 groups: G1 (n=10): CL in right ovary and ipsilateral embryo transfer, G2 (n=10): CL in right ovary and contralateral transfer, G3 (n=15): CL in left ovary and ipsilateral transfer, and G4 (n=8): CL in left ovary and contralateral transfer. Ten llamas were used as embryo donors, they were synchronized with LH (1ml), then superovulated with 1000 UI eCG and induced to luteolysis with PGF2α; after that, all of them were mated. The same day of mating, the recipients were treated with LH, with the purpose of synchronization with donors. Seven days postmating, the uterine horns were flushed to recover, evaluate and transfer the embryos. The nonsurgical embryo transfer was used the same day with fresh embryos. The results of pregnancy rate were 60% (G1) and 75% (G3) in recipient females with ipsilateral embryo transfer right and left respectively. On the other hand, contralateral embryo transfer right and left were 30% (G2) and 25% (G4) respectively. However, the differences did not reach significance (p>0.05) between G1 with G2, G3 and G4. Furthermore, G2 not differ (p>0.05) from G4. Whereas, there is difference (p less 0.05) between G3 with G2 and G4. These results indicate that pregnancy rate is major in llamas when the embryo transfer was to the uterine horn ipsilateral to the CL in the left ovary.
Tesis

Thesis (D.P.T.Sc.)--University of California, San Francisco and San Francisco State University, 2009.
Source: Dissertation Abstracts International, Volume: 71-02, Section: B, page: . Adviser: Nancy N. Byl.

Orientador: Donizeti Cesar Honorato
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Mais da metade das vítimas de Acidente Vascular Cerebral (AVC) apresentará algum grau de incapacidade, especialmente na extremidade superior (ES), e esta pode ser agravada pelos déficits sensoriais protopáticos e/ou epicríticos. Astereognosia, déficits das sensações táteis, dolorosas, térmicas e proprioceptivas são frequentes e podem afetar ambas as ES, resultando em prejuízos no alcance/preensão e dependência da orientação visual (OV). A redução do input sensorial da ES ipsilateral ao AVC é realizada para avaliar as conexões interhemisféricas e os efeitos na função sensório-motora das ES¿s. A crioterapia pode reduzir a velocidade de condução nervosa e minimizar o input sensorial da ES ipsilateral ao AVC. O objetivo do artigo 1 foi descrever o desempenho sensório-motor da ES de paciente pós-AVC crônico, na presença e ausência de OV. A ES foi avaliada pelo Protocolo de Desempenho Físico de Fugl-Meyer (FM), Avaliação Sensorial de Nottingham (ASN), 10 testes funcionais (TF) e testes de sequência motora (SM). A paciente apresentou déficits táteis, proprioceptivos e astereognosia na ES contralateral ao AVC e, a despeito do leve comprometimento motor, demonstrou lentidão/incapacidade de realização dos TF e SM na ausência da OV, caracterizando a paresia aferente. O objetivo do artigo 2 foi investigar as alterações sensoriais no complexo punho-mão ipsilateral de 28 sujeitos pós-AVC crônico e correlacioná-las com as disfunções sensório-motoras contralaterais à lesão, testes funcionais (com e sem OV), lateralidade do AVC e dominância manual. Foram aplicados a estesiometria, ASN, subescalas sensorial e motora de FM e testes funcionais. Os resultados revelaram distúrbios sensoriais ipsilaterais protopáticos e epicríticos em 64% dos indivíduos. Aqueles com lesão em hemisfério cerebral direito mostraram melhor sensação tátil na ES ipsilateral ao AVC e houve perda sensorial significativa na ES ipsilateral em dois sujeitos canhotos. Não houve correlação entre os déficits sensoriais das ES nem correlação entre os déficits sensoriais ipsilaterais e o comprometimento motor contralateral ao AVC. Os objetivos do artigo 3 foram aplicar a hipotermia por imersão da ES ipsilateral ao AVC (punho-mão) associada à intervenção sensorial (IS) na ES contralateral ao AVC crônico e avaliar os efeitos imediatos e em longo prazo. Foram acompanhados 27 sujeitos pós-AVC crônico nos grupos 1 (n=14) e 2 (n=13). O grupo 2 foi submetido à hipotermia por imersão do punho e mão ipsilaterais ao AVC com IS e o grupo 1 realizou IS (10 sessões). Foram mensurados estesiometria, FM, ASN, TF, SM, discriminação tátil, de peso, nível de desconforto e parâmetros hemodinâmicos. Os efeitos imediatos foram estabilidade hemodinâmica durante e após a hipotermia, ausência de alterações sensoriais na ES contralateral ao AVC, hipoestesia na ES ipsilateral (dermátomos C6 e C8) (p<0,05) e níveis de desconforto aceitáveis. Em longo prazo, tem-se a melhora nos TF (com e sem OV) e localização tátil, propriocepção consciente e função tátil nos dermátomos C6 e C7 na mão contralateral ao AVC do grupo 2 (p<0,05). O uso da hipotermia de imersão da ES ipsilateral associado à intervenção sensorial na ES contralateral ao AVC conduziu à melhora sensório-motora da ES oposta ao AVC crônico
Abstract: More than half the stroke victims will present some degree of disability, especially in the upper extremity (UE), and this may be influenced by somatosensory deficits. Astereognosis, deficits of tactile, painful, thermal and proprioceptive disturbances are frequent and can affect both ES, resulting in losses in the reach/grasp and dependence on visual guidance (VG). The reduction of ipsilesional UE¿s sensory input is performed to evaluate the interhemispherics connections and effects on sensorimotor function in stroke subjects. Cryotherapy can reduce the conduction velocity of sensory fibres and can minimise sensory input to the ipsilesional UE. The purpose of Article 1 was to describe the UE¿s sensorimotor performance in chronic post-stroke subject, in the presence and absence of VG. The contralesional UE was assessed by the Fugl-Meyer Assessment (FMA), Nottingham Sensory Assessment (NSA), 10 functional tests (FT) and motor sequence (MS). Despite the mild motor impairment, the patient presented tactile, proprioceptive dysfunctions and astereognosis in contralesional UE and slowness/failure to achieve FT and MS test in the absence of VG, characterizing the afferent paresis. The Article 2 investigated the changes in the ipsilesional wrist and hand of 28 stroke chronic stroke subjects and correlate them with the sensory-motor dysfunction contralateral to the lesion, functional tests (with and without VG), stroke laterality and hand dominance. The subjects were evaluated by esthesiometry, ASN, sensory and motor subscales FMA and FT. The results showed sensory disorders in 64% of individuals. Those with lesions in the right cerebral hemisphere showed better tactile sensation in the ipsilesional UE and significant sensory loss was found in the ipsilesional UE in two left-handed subjects. There was no correlation between sensory deficits of UE¿s or correlation between ipsilesional sensory deficits and contralesional motor impairment. The Article 3 applied immersion hypothermia of an ipsilesional upper extremity (UE) and sensorial intervention of contralesional UE of chronic post-stroke patients to evaluate the immediate hemodynamic, sensorimotor and long-term effects. The sample included 27 stroke patients allocated into group 1 (n=14), which received conventional physiotherapy for the contralesional UE, and group 2 (n=13), which was submitted to immersion hypothermia of the ipsilesional wrist and hand in ten sessions. Assessments were performed pre- and post-treatment and at follow-up using esthesiometry, FMA, NSA, FT, tactile and weight discrimination, MS, level of comfort and hemodynamic parameters. The immediate effects of immersion hypothermia were hemodynamic stability during and after each session, an absence of sensory changes in the UE and hypoesthesia in dermatomes, C6 and C8, of the ipsilesional UE (p<0.05), which maintained acceptable levels of comfort. Significant long-term improvements in test scores with and without visual guidance, using tactile localization, conscious proprioception and in tactile function of the C6 and C7 dermatomes of the contralesional hand in group 2 (p<0.05). Immersion hypothermia of the ipsilesional UE in chronic stroke patients is a safe, inexpensive and practical, with good patient adherence to the technique. The use of immersion hypothermia on the ipsilesional UE improved motor and sensitivity functions in the contralesional UE of chronic stroke patients
Doutorado
Ciencias Biomedicas
Doutora em Ciências Médicas

A dissertation presented in partial compliance with the requirements of the Master's Degree in Technology: Chiropractic, Durban Institute of Technology, 2003.
In recent years, sacroiliac syndrome has been widely accepted by many different health professions as one of the major contributors to low back pain. Manipulation to effect the relief of the condition has thus far proven to be one of the most effective methods. Comparatively little research has however been done on the different forms of physical therapy that can be used in conjunction with a manipulation so as to maximise its affect
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Performance of efficient and precise motor output requires proper planning of movement parameters as well as integration of sensory feedback. Peripheral sensory information is projected not only to parietal somatosensory areas but also to cortical motor areas, particularly the supplementary motor area (SMA). These afferent sensory pathways to the frontal cortices are likely involved in the integration of sensory information for assistance in motor program planning and execution. It is not well understood how and where sensory information from the limb contralateral to motor output is modulated, but the SMA is a potential cortical source as it is active both before and during motor output and is particularly involved in movements that require coordination and bilateral upper-limb selection and use. A promising physiological index of sensory inflow to the SMA is the frontal N30 component of the median nerve (MN) somatosensory-evoked potential (SEP), which is generated in the SMA. The SMA has strong connections with ipsilateral areas 2, 5 and secondary somatosensory cortex (S2) as well as ipsilateral primary motor cortex (M1). As such, the SMA proves a fruitful candidate to assess how sensory information is modulated across the upper-limbs during the various stages of motor output. This thesis inquires into how somatosensory information is modulated in both the SMA and primary somatosensory cortical areas (S1) during the planning and execution of a motor output contralateral to sensory input across the upper-limbs, and further, how and what effect ipsilateral primary motor cortex (iM1) has upon modulation of sensory inputs to the SMA.

Rhythmic arm cycling is known to suppress the Hoffmann (H-) reflex in the soleus muscles of stationary legs; however, it is still unclear if this suppression is modulated by the phase of movement in the cycle path. In the present study we investigated phase-dependent modulation of the Sol H-reflex induced by rhythmic arm cycling. Modulation of the Soleus H-reflex was examined at 12 phases of the cycle path in 4 conditions; static arm positioning, as well as 3 arm cycling conditions, bilateral, ipsilateral and contralateral. H-reflexes were evoked and recorded at constant motor wave amplitudes across the conditions. Suppression of Sol H-reflex amplitude was dependent (main effect p<0.0001) upon the phase of movement during arm cycling, but not during static positioning. Results suggest that locomotor central pattern generators may contribute to the phasic reflex modulation observed in this study.

Il existe des projections corticospinales (CS) vers les motoneurones (MNs) aussi bien contra- (c) qu’ipsilatérales (i). Les influences CSc sur les MNs du poignet sont connues pour être modulées entre autres par la position du poignet et les afférences cutanées. Pour cette raison, notre objectif était de vérifier si ces caractéristiques sont aussi valides pour les influences CSi. En utilisant la stimulation transcrânienne magnétique au niveau du cortex primaire droit, nous avons tout d’abord comparé les influences CSi sur les MNs des fléchisseurs du poignet à des positions maintenues de flexion et d’extension durant une tâche uni-manuelle ainsi que deux tâches bimanuelles, ceci chez des sujets droitiers (n=23). Nous avons ensuite comparé les influences CSi dans cinq tâches bi-manuelles de tenue d’objet durant lesquelles les sujets avaient à tenir entre leurs mains un bloc à la surface soit lisse, soit rugueuse, dont le poids était supporté ou non, ceci en position de flexion (n=21). Dans une tâche, un poids était ajouté au bloc lisse en condition non supportée pour amplifier les forces de préhension requises. Une modulation positiondépendante était observée au niveau des potentiels évoqués moteurs (iPEM), mais seulement lors de la tâche bi-manuelle quand les deux mains interagissaient via un bloc (p= 0.01). Une modulation basée sur la texture était également présente, quel que soit le support de poids, et le bloc lisse était associé avec des iPEMs plus importants en comparaison avec le bloc rugueux (p= 0.001). Ainsi, les influences CSi sur les MNs n’étaient modulées que lors des tâches bi-manuelles et dépendaient de la manière dont les mains interagissaient. De plus, les afférences cutanées modulaient les influences CSi facilitatrices et pourraient ainsi participer à la prise en main des objets. Il en est conclu que les hémisphères droit et gauche coopèrent durant les tâches bimanuelles impliquant la tenue d’objet entre les mains, avec la participation potentielle de projections mono-, et poly-synaptiques, transcallosales inclues. La possibilité de la contribution de reflexes cutanés et d’étirement (spinaux et transcorticaux) est discutée sur la base de la notion que tout mouvement découle du contrôle indirect, de la « référence » (referent control). Ces résultats pourraient être essentiels à la compréhension du rôle des interactions interhémisphériques chez les sujets sains et cliniques.
There are both contra- (c) and ipsilateral (i) corticospinal (CS) projections to motoneurons (MNs). There is evidence that cCS influences on wrist MNs are modulated by wrist position and cutaneous afferents. Thus, we aimed to test whether these findings are valid for iCS influences as well. Using transcranial magnetic stimulation applied over the right primary motor cortex, we first compared iCS influences on wrist flexor MNs at actively maintained flexion and extension wrist positions in one uni- and two bimanual tasks in right-handed subjects (n=23). We further compared iCS influences in five bimanual holding tasks in which subjects had to hold a smooth or coarse block between their hands, with or without its weight being supported, in flexion position (n=21). In one task, a weight was added to the unsupported smooth block to increase load forces. A position-dependent modulation of the short-latency motor evoked potential (iMEP) was observed, but only in the bimanual task when the two hands interacted through a block (p=0.01). A texture-dependent modulation was present regardless of the weight supported, and the smooth block was associated with larger iMEPs in comparison to the coarse block (p=0.001). Hence, iCS influences on MNs were modulated only in bimanual tasks and depended on how the two hands interacted. Furthermore, cutaneous afferents modulated facilitatory iCS influences and thus may participate to grip forces scaling and maintaining. It is concluded that the left and right cortices cooperate in bimanual tasks involving holding an object between the hands, with possible participation of mono- and poly-synaptic, including transcallosal projections to MNs. The possible involvement of spinal and trans-cortical stretch and cutaneous reflexes in bimanual tasks when holding an object is discussed based on the notion that indirect, referent control underlies motor actions. Results might be essential for the understanding of the role of intercortical interaction in healthy and neurological subjects.

Dissertation submitted in partial compliance with the requirements for the Masters Degree in Technology: Chiropractic, Technikon Natal, Durban, 1999.
The purpose of this study was to determine the relative effectiveness of adjusting the ipsilateral side of the fixated segment versus adjusting the side contralateral to that of the fixated segment, in patients with facet syndrome of the cervical spine, in terms of subjective and objective clinical fmdings, as well as patient comfort. The rationale for adjusting the cervical spine on the side contralateral to fixation is that the spinal dysfunction is of a soft tissue nature, as opposed to joint or bone. Thus the effectiveness of the spinal adjustment may be due to a reprogramming of the central nervous system, whereby the principal effect seems to be to stretch muscles to their normal resting length before spinal mobility can be restored. Adjusting the side opposite to the fixation may cause a sudden stretch of the muscle spindle resulting in a barrage of afferent impulses to the central nervous system, which reflexly turns down the gamma motor neuron tone. The resetting of the gamma motor neuron tone and resultant restoration of the muscle spindle's normal resting length, thereby helps to relieve the associated muscle spasm and possibly removes the fixation. This study was comprised of 30 subjects, all of whom were diagnosed with cervical facet syndrome. The subjects were randomly divided into two groups of 15 each with ap average age of24 years per group. The average male:female ratio was 1,1:1.
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