Academic literature on the topic 'Neurones de relais'
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Journal articles on the topic "Neurones de relais"
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Santoso, Putra, Masanori Nakata, Yoichi Ueta, and Toshihiko Yada. "Suprachiasmatic vasopressin to paraventricular oxytocin neurocircuit in the hypothalamus relays light reception to inhibit feeding behavior." American Journal of Physiology-Endocrinology and Metabolism 315, no. 4 (October 1, 2018): E478—E488. http://dx.doi.org/10.1152/ajpendo.00338.2016.
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Light synchronizes the body’s circadian rhythms by modulating the master clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. In modern lifestyles that run counter to normal circadian rhythms, the extended and/or irregular light exposure impairs circadian rhythms and, consequently, promotes feeding and metabolic disorders. However, the neuronal pathway through which light is coupled to feeding behavior is less elucidated. The present study employed the light exposure during the dark phase of the day in rats and observed its effect on neuronal activity and feeding behavior. Light exposure acutely suppressed food intake and elevated c-Fos expression in the AVP neurons of SCN and the oxytocin (Oxt) neurons of paraventricular nucleus (PVN) in the hypothalamus. The light-induced suppression of food intake was abolished by blockade of the Oxt receptor in the brain. Retrograde tracer analysis demonstrated the projection of SCN AVP neurons to the PVN. Furthermore, intracerebroventricular injection of AVP suppressed food intake and increased c-Fos in PVN Oxt neurons. Intra-PVN injection of AVP exerted a stronger anorexigenic effect than intracerebroventriclar injection. AVP also induced intracellular Ca2+ signaling and increased firing frequency in Oxt neurons in PVN slices. These results reveal the novel neurocircuit from SCN AVP to PVN Oxt that relays light reception to inhibition of feeding behavior. This light-induced neurocircuit may serve as a pathway for forming the circadian feeding rhythm and linking irregular light exposure to arrhythmic feeding and, consequently, obesity and metabolic diseases.
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Aggarwal, Sanya, Celion Tang, Kristen Sing, Hyun Wook Kim, Robert P. Millar, and Javier A. Tello. "Medial Amygdala Kiss1 Neurons Mediate Female Pheromone Stimulation of Luteinizing Hormone in Male Mice." Neuroendocrinology 108, no. 3 (December 10, 2018): 172–89. http://dx.doi.org/10.1159/000496106.
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Background/Aims: The medial amygdala (MeA) responds to olfactory stimuli and alters reproductive physiology. However, the neuronal circuit that relays signals from the MeA to the reproductive axis remains poorly defined. This study aimed to test whether MeA kisspeptin (MeAKiss) neurons in male mice are sensitive to sexually relevant olfactory stimuli and transmit signals to alter reproductive physiology. We also investigated whether MeAKiss neurons have the capacity to elaborate glutamate and GABA neurotransmitters and potentially contribute to reproductive axis regulation. Methods: Using female urine as a pheromone stimulus, MeAKiss neuronal activity was analysed and serum luteinizing hormone (LH) was measured in male mice. Next, using a chemogenetic approach, MeAKiss neurons were bi-directionally modulated to measure the effect on serum LH and evaluate the activation of the preoptic area. Lastly, using in situ hybridization, we identified the proportion of MeAKiss neurons that express markers for GABAergic (Vgat) and glutamatergic (Vglut2) neurotransmission. Results: Male mice exposed to female urine showed a two-fold increase in the number of c-Fos-positive MeAKiss neurons concomitant with raised LH. Chemogenetic activation of MeAKiss neurons significantly increased LH in the absence of urine exposure, whereas inhibition of MeAKiss neurons did not alter LH. In situ hybridization revealed that MeAKiss neurons are a mixed neuronal population in which 71% express Vgat mRNA, 29% express Vglut2 mRNA, and 6% express both. Conclusions: Our results uncover, for the first time, that MeAKiss neurons process sexually relevant olfactory signals to influence reproductive hormone levels in male mice, likely through a complex interplay of neuropeptide and neurotransmitter signalling.
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Yoshioka, Takashi, Jonathan B. Levitt, and Jennifer S. Lund. "Independence and merger of thalamocortical channels within macaque monkey primary visual cortex: Anatomy of interlaminar projections." Visual Neuroscience 11, no. 3 (May 1994): 467–89. http://dx.doi.org/10.1017/s0952523800002406.
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AbstractAn important issue in understanding the function of primary visual cortex in the macaque monkey is how the several efferent neuron groups projecting to extrastriate cortex acquire their different response properties. To assist our understanding of this issue, we have compared the anatomical distribution of VI intrinsic relays that carry information derived from magno- (M) and parvocellular (P) divisions of the dorsal lateral geniculate nucleus between thalamic recipient neurons and interareal efferent neuron groups within area VI. We used small, iontophoretic injections of biocytin placed in individual cortical laminae of area VI to trace orthograde and retrograde inter- and intralaminar projections. In either the same or adjacent sections, the tissue was reacted for cytochrome oxidase (CO), which provides important landmarks for different efferent neuron populations located in CO rich blobs and CO poor interblobs in laminae ⅔, as well as defining clear boundaries for the populations of efferent neurons in laminae 4A and 4B. This study shows that the interblobs, but not the blobs, receive direct input from thalamic recipient 4C neurons; the interblobs receive relays from mid 4C neurons (believed to receive convergent M and P inputs), while blobs receive indirect inputs from either M or P (or both) pathways through layers 4B (which receives M relays from layer 4Cα) and 4A (which receives P relays directly from the thalamus as well as from layer 4Cβ). The property of orientation selectivity, most prominent in the interblob regions and in layer 4B, may have a common origin from oriented lateral projections made by mid 4C spiny stellate neurons. While layer 4B efferents may emphasize M characteristics and layer 4A efferents emphasize P characteristics, the dendrites of their constituent pyramidal neurons may provide anatomical access to the other channel since both blob and interblob regions in layers ⅔ have anatomical access to M and P driven relays, despite functional differences in the way these properties may be expressed in the two compartments.
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Thion, Morgane S., Florent Ginhoux, and Sonia Garel. "Microglia and early brain development: An intimate journey." Science 362, no. 6411 (October 11, 2018): 185–89. http://dx.doi.org/10.1126/science.aat0474.
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Cross-talk between the nervous and immune systems has been well described in the context of adult physiology and disease. Recent advances in our understanding of immune cell ontogeny have revealed a notable interplay between neurons and microglia during the prenatal and postnatal emergence of functional circuits. This Review focuses on the brain, where the early symbiotic relationship between microglia and neuronal cells critically regulates wiring, contributes to sex-specific differences in neural circuits, and relays crucial information from the periphery, including signals derived from the microbiota. These observations underscore the importance of studying neurodevelopment as part of a broader framework that considers nervous system interactions with microglia in a whole-body context.
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Kutikov, Artem B., Simon W. Moore, Richard T. Layer, Pamela E. Podell, Nithya Sridhar, Andrea J. Santamaria, Alex A. Aimetti, Christoph P. Hofstetter, Thomas R. Ulich, and James D. Guest. "Method and Apparatus for the Automated Delivery of Continuous Neural Stem Cell Trails Into the Spinal Cord of Small and Large Animals." Neurosurgery 85, no. 4 (August 29, 2018): 560–73. http://dx.doi.org/10.1093/neuros/nyy379.
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AbstractBackgroundImmature neurons can extend processes after transplantation in adult animals. Neuronal relays can form between injected neural stem cells (NSCs) and surviving neurons, possibly improving recovery after spinal cord injury (SCI). Cell delivery methods of single or multiple bolus injections of concentrated cell suspensions thus far tested in preclinical and clinical experiments are suboptimal for new tract formation. Nonuniform injectate dispersal is often seen due to gravitational cell settling and clumping. Multiple injections have additive risks of hemorrhage, parenchymal damage, and cellular reflux and require additional surgical exposure. The deposition of multiply delivered cells boluses may be uneven and discontinuous.ObjectiveTo develop an injection apparatus and methodology to deliver continuous cellular trails bridging spinal cord lesions.MethodsWe improved the uniformity of cellular trails by formulating NSCs in hyaluronic acid. The TrailmakerTM stereotaxic injection device was automatized to extend a shape memory needle from a single-entry point in the spinal cord longitudinal axis to “pioneer” a new trail space and then retract while depositing an hyaluronic acid-NSC suspension. We conducted testing in a collagen spinal models, and animal testing using human NSCs (hNSCs) in rats and minipigs.ResultsContinuous surviving trails of hNSCs within rat and minipig naive spinal cords were 12 and 40 mm in length. hNSC trails were delivered across semi-acute contusion injuries in rats. Transplanted hNSCs survived and were able to differentiate into neural lineage cells and astrocytes.CONCLUSIONThe TrailmakerTM creates longitudinal cellular trails spanning multiple levels from a single-entry point. This may enhance the ability of therapeutics to promote functional relays after SCI.
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Ren, K., A. Randich, and G. F. Gebhart. "Electrical stimulation of cervical vagal afferents. I. Central relays for modulation of spinal nociceptive transmission." Journal of Neurophysiology 64, no. 4 (October 1, 1990): 1098–114. http://dx.doi.org/10.1152/jn.1990.64.4.1098.
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1. Supraspinal relays for vagal afferent modulation of responses of spinal dorsal horn neurons to 50 degrees C heating of the skin were examined by the use of nonselective, reversible local anesthesia or soma-selective, irreversible neurotoxic damage of neural tissue. Eighty-five neurons were isolated in the lumbar spinal dorsal horn of 80 pentobarbital-anesthetized, paralyzed rats. All neurons studied had receptive fields on the glabrous skin of the plantar surface of the ipsilateral hind paw and responded to mechanical stimuli of both low and high intensity as well as noxious thermal stimulation. 2. Intensity-dependent modulation by vagal afferent stimulation (VAS) of neuronal responses to heating of the skin was established. Responses of 40 units were facilitated by low and inhibited by greater intensities of VAS. Another 36 units were only inhibited by VAS, and four were only facilitated. 3. Local anesthesia of the dorsolateral pons by bilateral microinjections of lidocaine (4%, 0.5 microliter) were made to examine the contribution of this area to VAS-produced spinal modulation. The microinjection of lidocaine bilaterally into the ventral locus coeruleus/subcoeruleus (LC/SC) reversibly and significantly attenuated VAS-produced inhibition of unit responses to heat from 63 to 89% of control and abolished VAS-produced facilitation. The microinjection of lidocaine bilaterally into the dorsal LC had no significant effect on VAS-produced modulation of spinal dorsal horn neurons. 4. Ibotenic acid (10 micrograms, 0.5 microliter) was microinjected into the dorsolateral pons to determine the relative contributions of cell bodies in this area to VAS-produced spinal modulation. Unilateral microinjection of ibotenic acid into the LC/SC ipsilateral to the vagus nerve stimulated had no significant effect on VAS-produced inhibition but significantly attenuated VAS-produced facilitation of unit responses to heat. Bilateral microinjections of ibotenic acid significantly attenuated VAS-produced inhibition of unit responses to heat from 48 to 94% of control. 5. Local anesthesia of the medial rostroventral medulla (RVM), primarily the nucleus raphe magnus (NRM), significantly attenuated VAS-produced inhibition of unit responses to heat from 55 to 87% of control but had no significant effect on VAS-produced facilitation. Microinjection of ibotenic acid into the RVM also significantly reduced VAS-produced inhibition of unit responses to heat. No significant change in VAS-produced spinal modulation was found after lidocaine microinjection into areas dorsal to the NRM, the nucleus raphe pallidus, or the olivary nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)
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Imbrosci, Barbara, Angela Neitz, and Thomas Mittmann. "Physiological Properties of Supragranular Cortical Inhibitory Interneurons Expressing Retrograde Persistent Firing." Neural Plasticity 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/608141.
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Neurons are polarized functional units. The somatodendritic compartment receives and integrates synaptic inputs while the axon relays relevant synaptic information in form of action potentials (APs) across long distance. Despite this well accepted notion, recent research has shown that, under certain circumstances, the axon can also generate APs independent of synaptic inputs at axonal sites distal from the soma. These ectopic APs travel both toward synaptic terminals and antidromically toward the soma. This unusual form of neuronal communication seems to preferentially occur in cortical inhibitory interneurons following a period of intense neuronal activity and might have profound implications for neuronal information processing. Here we show that trains of ectopically generated APs can be induced in a large portion of neocortical layer 2/3 GABAergic interneurons following a somatic depolarization inducing hundreds of APs. Sparsely occurring ectopic spikes were also observed in a large portion of layer 1 interneurons even in absence of prior somatic depolarization. Remarkably, we found that interneurons which produce ectopic APs display specific membrane and morphological properties significantly different from the remaining GABAergic cells and may therefore represent a functionally unique interneuronal subpopulation.
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Li, Cheng-Shu, Da-Peng Lu, and Young K. Cho. "Descending projections from the nucleus accumbens shell excite activity of taste-responsive neurons in the nucleus of the solitary tract in the hamster." Journal of Neurophysiology 113, no. 10 (June 2015): 3778–86. http://dx.doi.org/10.1152/jn.00362.2014.
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The nucleus of the solitary tract (NST) and the parabrachial nuclei (PbN) are the first and second relays in the rodent central taste pathway. A series of electrophysiological experiments revealed that spontaneous and taste-evoked activities of brain stem gustatory neurons are altered by descending input from multiple forebrain nuclei in the central taste pathway. The nucleus accumbens shell (NAcSh) is a key neural substrate of reward circuitry, but it has not been verified as a classical gustatory nucleus. A recent in vivo electrophysiological study demonstrated that the NAcSh modulates the spontaneous and gustatory activities of hamster pontine taste neurons. In the present study, we investigated whether activation of the NAcSh modulates gustatory responses of the NST neurons. Extracellular single-unit activity was recorded from medullary neurons in urethane-anesthetized hamsters. After taste response was confirmed by delivery of sucrose, NaCl, citric acid, and quinine hydrochloride to the anterior tongue, the NAcSh was stimulated bilaterally with concentric bipolar stimulating electrodes. Stimulation of the ipsilateral and contralateral NAcSh induced firings from 54 and 37 of 90 medullary taste neurons, respectively. Thirty cells were affected bilaterally. No inhibitory responses or antidromic invasion was observed after NAcSh activation. In the subset of taste cells tested, high-frequency electrical stimulation of the NAcSh during taste delivery enhanced taste-evoked neuronal firing. These results demonstrate that two-thirds of the medullary gustatory neurons are under excitatory descending influence from the NAcSh, which is a strong indication of communication between the gustatory pathway and the mesolimbic reward pathway.
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Higo, Shimpei, Satoko Aikawa, Norio Iijima, and Hitoshi Ozawa. "Rapid modulation of hypothalamic Kiss1 levels by the suckling stimulus in the lactating rat." Journal of Endocrinology 227, no. 2 (September 9, 2015): 105–15. http://dx.doi.org/10.1530/joe-15-0143.
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In mammals, lactation suppresses GnRH/LH secretion resulting in transient infertility. In rats, GnRH/LH secretion is rescued within 18–48 h after pup separation (PS) and rapidly re-suppressed by subsequent re-exposure of pups. To elucidate the mechanisms underlying these rapid modulations, changes in the expression of kisspeptin, a stimulator of GnRH secretion, in several lactating conditions (normal-lactating; 4-h PS; 18-h PS; 4-h PS +1-h re-exposure of pups; non-lactating) were examined usingin situhybridization. PS for 4 h or 18 h increasedKiss1expressing neurons in both the anteroventral periventricular nucleus (AVPV) and the arcuate nucleus (ARC), and subsequent exposure of pups re-suppressedKiss1in the AVPV. A change inKiss1expression was observed prior to the reported time of the change in GnRH/LH, indicating that the change in GnRH/LH results from changes in kisspeptin. We further examined the mechanisms underlying the rapid modulation ofKiss1. We first investigated the possible involvement of ascending sensory input during the suckling stimulus. Injection of the anterograde tracer to the subparafascicular parvocellular nucleus (SPFpc) in the midbrain, which relays the suckling stimulus, revealed direct neuronal connections between the SPFpc and kisspeptin neurons in both the AVPV and ARC. We also examined the possible involvement of prolactin (PRL). Administration of PRL for 1 h suppressedKiss1expression in the AVPV but not in the ARC. These results indicate that suckling stimulus rapidly modulatesKiss1expression directly via neuronal connections and indirectly through serum PRL, resulting in modulation in GnRH/LH secretion.
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Patel, Ryan, and Anthony H. Dickenson. "Neuronal hyperexcitability in the ventral posterior thalamus of neuropathic rats: modality selective effects of pregabalin." Journal of Neurophysiology 116, no. 1 (July 1, 2016): 159–70. http://dx.doi.org/10.1152/jn.00237.2016.
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Neuropathic pain represents a substantial clinical challenge; understanding the underlying neural mechanisms and back-translation of therapeutics could aid targeting of treatments more effectively. The ventral posterior thalamus (VP) is the major termination site for the spinothalamic tract and relays nociceptive activity to the somatosensory cortex; however, under neuropathic conditions, it is unclear how hyperexcitability of spinal neurons converges onto thalamic relays. This study aimed to identify neural substrates of hypersensitivity and the influence of pregabalin on central processing. In vivo electrophysiology was performed to record from VP wide dynamic range (WDR) and nociceptive-specific (NS) neurons in anesthetized spinal nerve-ligated (SNL), sham-operated, and naive rats. In neuropathic rats, WDR neurons had elevated evoked responses to low- and high-intensity punctate mechanical stimuli, dynamic brushing, and innocuous and noxious cooling, but less so to heat stimulation, of the receptive field. NS neurons in SNL rats also displayed increased responses to noxious punctate mechanical stimulation, dynamic brushing, noxious cooling, and noxious heat. Additionally, WDR, but not NS, neurons in SNL rats exhibited substantially higher rates of spontaneous firing, which may correlate with ongoing pain. The ratio of WDR-to-NS neurons was comparable between SNL and naive/sham groups, suggesting relatively few NS neurons gain sensitivity to low-intensity stimuli leading to a “WDR phenotype.” After neuropathy was induced, the proportion of cold-sensitive WDR and NS neurons increased, supporting the suggestion that changes in frequency-dependent firing and population coding underlie cold hypersensitivity. In SNL rats, pregabalin inhibited mechanical and heat responses but not cold-evoked or elevated spontaneous activity.
Dissertations / Theses on the topic "Neurones de relais"
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Dufresne, Caroline. "Relais des informations sensorielles dans le système paralemniscal : études in vivo et in vitro chez le rat." Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23798/23798.pdf.
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Jiang, Tao. "Propriétés d'intégration spatiale des neurones-relais du bulbe olfactif chez la grenouille : corrélations morphofonctionnelles." Lyon 1, 1989. http://www.theses.fr/1989LYO10109.
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La recherche concerne les proprietes d'intagration spatiale des informations peripheriques par les deutoneurones du bulbe olfactif et les correlations morphofonctionnelles relatives a ces neurones. Nous avons etabli un modele experimental chez la grenouille par la stimulation electrique separee ou conjointe de 9 sites de l'eminence epitheliale et l'enregistrement unitaire, dans le bulbe olfactif, de l'activite extracellulaire et intracellulaire de neurones identifies. Les resultats obtenus dans ces conditions experimentales revelent que: 1. Aucune region de l'epithelium ventral n'a de relation topologique privilegiee avec une region particuliere du bulbe olfactif; 2. Les deutoneurones ont des champs recepteurs peripheriques de tailles variables. A l'interieur de la surface exploree, chaque champ recepteur est inferieur en moyenne aux 2/3 de l'ensemble; 3. La nature (excitation ou inhibition) des reponses d'un deutoneurone ne change pas avec la localisation de la stimulation; 4. L'integration spatiale obtenue par stimulation conjointe de plusieurs sites est une sommation non lineaire des effets propres a chaque site; les deutoneurones bulbaires ne forment pas une population homogene. Ils peuvent etre repartis, d'apres leur reaction, a une stimulation ponctuelle au niveau epithelial, en au moins deux groupes. De plus, cette heterogeneite electrophysiologique a sa correspondance en morphologie
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Rateau, Yann. "Effet de la modulation de l'activité thalamique par la sérotonine pendant la mise en place du champs de barils chez la souris nouveau-née." Paris 6, 2007. http://www.theses.fr/2007PA066651.
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Le champ de barils des rongeurs apparaît pendant la première semaine postnatale dans la couche IV du cortex somatosensoriel primaire (S1). L'excès de sérotonine (5HT) pendant cette semaine empêche la formation des barils. Nous avons étudié l’effet de la 5HT sur l’excitabilité des neurones du noyau Ventropostéromédial du thalamus (VPM) pendant le développement des barils. Par enregistrement en patch-clamp, nous avons observé que la 5HT dépolarise les neurones VPM selon deux mécanismes. Nos résultats montrent que la 5HT active un courant sensible à l’hyperpolarisation (Ih) et que la dépolarisation de ces neurones est associée à la fermeture d’une conductance potassique via l’activation d’un récepteur 5 HT7 et l’AMPc, cet effet étant d’autant plus marqué que l’animal est jeune. Dans le noyau réticularis (nRT), nous avons décrit un courant cationique activé par hyperpolarisation, de cinétique lente et sensible au césium (2 mM) et au ZD7288 (50 µM) et comme le courant Ih sensible à l’AMPc.
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Smetana, Bedřich. "Algebraizace a parametrizace přechodových relací mezi strukturovanými objekty s aplikacemi v oblasti neuronových sítí." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-433543.
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The dissertation thesis investigates the modeling of the neural network activity with a focus on a multilayer forward neural network (MLP – Multi Layer Perceptron). In this often used structure of neural networks, time-varying neurons are used, along with an analogy in modeling hyperstructures of linear differential operators. Using a finite lemma and defined hyperoperation, a hyperstructure composed of neurons is defined for a given transient function. There are examined their properties with an emphasis on structures with a layout.
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Nasr, Esfahani Ali. "Validation of a transgenic mouse line with knockdown of mGluR5 selectively in dopamine D1receptor expressing neurons." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-65665.
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One of the main difficulties of addiction treatment is the high risk of relapse even after a longabstinence and fully detoxification. Therefore, discovering the underlying molecular principlesof relapse is essential. The metabotropic glutamate receptor, mGluR5, is considered to beinvolved in this aspect. One of the brain structures expressing mGluR5 is the striatum, an areawith well-established role in addiction which is largely composed of medium-sized spinyneurons (MSNs). These neurons are basically divided into two major subpopulationscharacterized based on their projections and protein properties. It is known that the mGluR5receptor is expressed on both subpopulations of MSNs. Consequently, it can be used to establishthe proportional contribution of each of MSNs subpopulations in relapse to addiction. In ourconstellation, we have generated a mouse line designed to have a selective mGluR5 knock-downin one of these subpopulations – the dopamine D1 receptor (D1R) expressing neurons. It hashowever been unclear if the expression of the transgene is indeed limited to only D1R-expressingneurons. By immunofluorescence technique, I here show that the construct is expressed only inMSNs and is restricted to the D1R-expressing cell population in the striatum. Thus the transgenicmouse line is a good tool for the study of mGluR5 selectively in D1R expressing neurons.
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Palou, Serra Aina. "Estudi en mostres humanes i en cultius neuronals d’indicadors del sistema glutamatèrgic i dopaminèrgic en relació a l’exposició prolongada a contaminants orgànics tòxics persistents." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/109152.
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Aquesta tesi neix d’una preocupació creixent: com estan incidint certs contaminants presents al medi ambient (conseqüència de diverses activitats humanes) en la salut de les persones i més en concret en el sistema nerviós. Aquesta tesi té com a objectiu aprofundir en l’estudi dels efectes de certs contaminants orgànics tòxics persistents en diferents paràmetres del sistema glutamatèrgic i dopaminèrgic quan es troben presents a baixes concentracions i de manera perllongada, en especial èmfasi a l’etapa del desenvolupament. La tesi s’ha dividit en tres parts. En la primera part s’estudia l’alteració d’indicadors del sistema glutamatèrgic en mostres humanes de placenta i sang de cordó umbilical en relació als seus nivells de mercuri i contaminants organoclorats. Aquesta primera part s’ha realitzat amb mostres humanes de sang de cordó umbilical i placenta que provenien d’ una cohort de naixement mare-fill del grup de València del projecte INMA (Infància i Medi Ambient) prèviament analitzades pel seu contingut en contaminants organoclorats i mercuri total (T-Hg). Partint del fet que el MeHg inhibeix el transportador de glutamat al sistema nerviós, i que altres contaminants orgànics persistents també actuen en el sistema glutamatèrgic, es va estudiar si els nivells d’aminoàcids excitadors en sang de cordó umbilical, glutamat i aspartat, es veien alterats en funció de les concentracions de contaminants organoclorats i/o T-Hg i també si el transportador de glutamat en placenta es veia inhibit davant l’exposició a contaminants. Es va demostrar que existia una correlació significativament negativa entre la suma de contaminants organoclorats, el PCB 138 i el β-HCH analitzats en sang de cordó umbilical i la concentració de glutamat. Per altre banda, es va observar, que en les mostres amb baix nivell de metilmercuri (<7µg/L) aquesta associació es pronunciava, mentre que en les mostres amb alt contingut (≥21µg/L) l’associació es perdia, insinuant-se un efecte compensatori entre MeHg i contaminants organoclorats. Finalment, es va demostrar com el MeHg inhibia completament el transport de glutamat amb una IC50 de l’ordre de micromolar, mentre que el PCB138 i el β-HCH l’inhibien parcialment, però amb una IC50 de l’ordre de nanomolar. A la segona part es van estudiar els efectes de l’exposició prolongada in vitro a concentracions subcitotòxiques de PCB138 i hexaclorciclohexà (HCH) en transportadors i receptors glutamatèrgics en cultius primaris de neurones corticals de ratolí. Per tal d’estudiar la funcionalitat dels receptors glutamatèrgics es va mesurar l’entrada de calci activada pels corresponents agonistes en presència i/o absència dels contaminants PCB 138 i el γ-HCH (lindà). El PCB 138 i el γ-HCH (lindà) en exposicions agudes van potenciar el senyal de calci mediat pel receptor glutamatèrgic d’NMDA (N-metil-D–aspartat). L’exposició prolongada (6 dies in vitro, DIV)a concentracions subcitotòxiques de PCB 138 i el γ-HCH (lindà) durant el procés de maduració neuronal va augmentar el senyal de calci intracel•lular induït per NMDA respecte el control. L’expressió de la subunitat NR1 del receptor en el procés de maduració va disminuir en presència dels contaminants durant 6 DIV respecte el control. En la tercera part es va estudiar l’efecte de l’exposició prolongada a dosis subcitotòxiques de PCB138 i γ-HCH en cèl•lules humanes de neuroblastoma SH-SY5Y diferenciades amb àcid retinoic. Es va observar que el γ-HCH disminuïa de manera dosi-dependent l’expressió de mRNA i l’expressió proteica del transportador vesicular de monoamina 2 (VMAT2) i el receptor de dopamina D2 (DRD2 L i S) quan es trobava present en aquestes cèl•lules durant el període de diferenciació durant 6DIV. En canvi el PCB 138 no va modificar la expressió de VMAT2 ni de DRD2. Aquest estudi aporta més informació dels efectes que exerceixen certs contaminants organoclorats, reforçant altres estudis àmpliament descrits on es posa de manifest l’impacte de dits contaminants en la salut humana.This thesis appears as a consequence of a growing concern: how the environmental contaminants are affecting health and particularly the nervous system. The aim of this thesis is to study how certain persistent organic toxic pollutants affect dopaminergic and glutamatergic parameters when they are present at low-doses and long-time, especially in the developmental period. The thesis is divided in three parts. In the first part it has been determined the excitatory aminoacid levels (glutamate and aspartate) in 40 human umbilical cord blood samples from a Spanish cohort and their levels have been related to the total mercury (T-Hg) and organochlorine compounds (OCs) content. It has also been studied the inhibition of glutamate transport in human placentas by methylmercury (MeHg), polychlorobiphenyl 138 (PCB 138) and beta-hexaclorocyclohexane (β-HCH). T-Hg did not show a significant correlation with glutamate nor aspartate levels in cord blood, but PCB138, β-HCH, and the sum of the 8 OCs analyzed showed a significant negative correlation with the levels of glutamate. A significant compensatory effect between T-Hg and PCB138, 4,4’-DDE and the sum of the 8 OCs analyzed has been observed. We also demonstrate that MeHg inhibit completely the glutamate transport while PCB138 andβ-HCH inhibited partially but with nanomolar affinity. In the second part we studied the effects that PCB138 and (HCH) produced on the glutamatergic receptors in primary cultures of cortical neurons (CTX) exposed to low concentrations for long period (6 days in vitro, DIV). We show that PCB 138 and lindane increased the calcium signal induced by NMDA (N-methyl-D-aspartate) in acute and long-period expositions. Also we show that PCB 138 and lindane reduced the expression of NR1 subunit in CTX cultures when they are present during 6 DIV. In the third part, we studied the effect of prolonged exposure of PCB 138 and lindane on dopaminergic receptors D2 (DRD2) (S & L isoforms) and the vesicular monoamine transporter 2 (VMAT2) on SH-SY5Y human neuroblastoma cells line differentiated with retinoic acid. Exposure to γ-HCH during the differentiation period decreased in a dose-dependent way the mRNA and protein expression of VMAT2 and DRD2 (L and S). PCB 138 did not modify the expression of VMAT2 or DRD2. This study provides information on the effects of certain organochlorine pollutants on glutamate and dopamine processes, reinforcing other studies which described the impact of these pollutants on human health.
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Silva, Pablo Augusto. "O mundo como catastrofe e representação : testemunho, trauma e violencia na literatura do sobrevivente." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/279004.
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Orientador: Maria Lygia Quartim de MoraesDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas
Made available in DSpace on 2018-08-07T03:43:04Z (GMT). No. of bitstreams: 1 Silva_PabloAugusto_M.pdf: 882543 bytes, checksum: 8dffa4b5e16f321374f88b76ace65eb8 (MD5) Previous issue date: 2006
Resumo: Este trabalho é uma análise de obras autobiográficas de indivíduos que tiveram uma experiência traumática com a realidade, vivenciada nas instituições carcerárias do Brasil contemporâneo (1970-2000). Há nestas narrativas, enquanto exercícios de rememoração, uma grande riqueza que nos permite compreender a trajetória social de indivíduos que sofreram a experiência - única - do trauma. O encarceramento como o centro de suas vidas, o evento que no bem e no mal marcou toda a sua existência. Esse novo modo de fazer literatura - que pode ser chamado de literatura carcerária e/ou das prisões - emerge nos anos 1980, ganhando visibilidade principalmente no início dos anos 1990. Atualmente, vem tendo êxito no mercado editorial, despertando e dividindo o interesse da crítica cultural pelo tema. Portadoras de um teor testemunhal - como as obras de escritores que tratam da experiência judaica nos campos de concentração (Lagers) durante a 11 Guerra Mundial, e de escritores latino-americanos que narram a violência sofrida durante as ditaduras nos anos 1950/60/70 -, tais autobiografias são, antes de tudo, o testemunho do Sobrevivente da Era da Catástrofe, como pode ser resumido o breve século xx
Abstract: This work consists of an analysis of auto-biographical accounts written by individuais who have undergone traumatic experiences with reality in correctional facilities in contemporary Brazil (1970-2000). These accounts, as exercises in recollection, contain a great wealth of material and enable us to better understand the social history of individuais who have undergone a unique experience of trauma. The trauma, in this case, is the experience of imprisonment as the center of their lives, the event that, for better or for worse, marked their entire existence. This new mode of literary production - known as prison literature - arose in the 1980s and took on greater visibility in the early 1990s. It has been successful on the editorial market and aroused the interest of cultural critics of the topic. It has also been the object of some controversy. These autobiographies are similar to the writings of Jews who described their experiences in concentration camps (Lagers) during World War 11, and like a number of Latin-American writers who described the violence they were subjected to during the dictatorships of the 1950s, 1960s and 1970s. Above ali else, the accounts are the testimony of Survivors of the Era of Catastrophe, as the brief 20th century might be called.
Mestrado
Sociologia
Mestre em Sociologia
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Meléndez, Catalán Blai. "Relative music loudness estimation in TV broadcast audio using deep learning: an industrial perspective." Doctoral thesis, Universitat Pompeu Fabra, 2021. http://hdl.handle.net/10803/671425.
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Under the current copyright management business model, broadcasters are taxed by the corresponding copyright management organization according to the percentage of music they broadcast, and the collected money is then distributed among the copyright holders of that music. In the specific case of TV broadcasts, whether a musical piece is played in the foreground or the background is often a relevant factor that affects the amount of money collected and distributed. In recent years, the music industry is increasingly adopting technological solutions to automatize this process. We have conducted this industrial PhD at BMAT, a company that has an active role in providing these solutions: since 2015, this company has been offering a service that currently monitors about 4300 radio stations and TV channels to automatically detect the presence of music, and to classify it as foreground or background music. We name this task relative music loudness estimation. From an industrial point of view, this thesis focuses on the improvement of the technology behind the service; and from the academic point of view, it pursues the introduction and promotion of the task in the research field of music information retrieval, and provides computational approaches to it.
The industrial and academic contributions of this thesis result from logical steps towards these goals. We first create BAT: a new open-source, web-based tool for the efficient annotation of audio events and their partial loudness in the presence of other simultaneous events. We use BAT to annotate two datasets: one private and the other public. We use the private dataset for training in the development of BMAT's new relative music loudness estimation algorithm called the Deep Music Detector. The Deep Music Detector represents the first application of deep learning within BMAT, and provides a significant boost in performance with respect to its predecessor. The public dataset, called OpenBMAT, is released in order to foster transparent, comparable and reproducible research on the task of relative music loudness estimation. We use OpenBMAT in our proposal of a novel deep learning solution to this task based on an architecture that combines regular convolutional neural networks, and temporal convolutional networks. This architecture is able to extract robust features from a time-frequency representation of an audio file, and then model them as temporal sequences, producing state-of-the-art results with an efficient usage of the network's parameters. Finally, this thesis also offers a review of the concepts, resources and literature about tasks related to the detection of music.En l'actual model de negoci de la gestió de drets d'autor, les emissores paguen una certa quantitat d'impostos a l'organització de drets d'autor corresponent que depèn del percentatge de música que emeten. Els diners recaptats d'aquesta manera es distribueixen entre els propietaris dels drets d'aquesta música. En el cas específic de les emissores de televisió, el fet que la música s'emeti en primer o segon pla és sovint un factor rellevant que afecta la quantitat de diners recaptada i distribuïda. Recentment, la indústria musical està optant cada cop més per solucions tecnològiques que automatitzen aquest procés. Hem realitzat aquest doctorat industrial a BMAT, una empresa que proveeix aquest tipus de solucions. Des de 2015, aquesta empresa ofereix un servei que actualment monitora al voltant de 4300 canals de ràdio i televisió per detectar automàticament la presència de música i identificar si es troba en primer o segon pla. A aquesta tasca l'anomenem estimació del volum relatiu de la música. Des del punt de vista industrial aquesta tesi se centra en la millora de la tecnologia que hi ha darrere d'aquest servei, mentre que des del punt de vista acadèmic persegueix la introducció i promoció de la tasca en el camp de recerca del music information retrieval, i hi aporta solucions tecnològiques. Les contribucions industrials i acadèmiques d'aquesta tesi són el resultat d'uns passos lògics, encaminats cap a la consecució aquests objectius. El primer pas és la creació de BAT: una nova eina web i de codi obert per a l'anotació d'esdeveniments acústics i del seu volum parcial. El segon pas consisteix a utilitzar BAT per anotar dos datasets: un de privat i un de públic. El dataset privat l'usem per a entrenament en el desenvolupament del Deep Music Detector, el nou algorisme d'estimació del volum relatiu de la música de BMAT. El Deep Music Detector representa la primera aplicació d'aprenentatge profund dins de BMAT, i aporta una millora substancial del servei respecte al seu predecessor. El dataset públic, anomenat OpenBMAT, es publica per promoure una recerca transparent, comparable i reproduïble en la tasca d'estimació del volum relatiu de la música. A més a més, nosaltres l'usem en la nostra proposta d'una nova solució a aquesta tasca, que es basa en una arquitectura d'aprenentatge profund que combina les xarxes neuronals convolucionals estàndard amb les xarxes convolucionals temporals. Aquesta arquitectura permet extreure descriptors robustos a partir d'una representació temporal-freqüencial d'un fitxer d'àudio i modelar-los com a seqüència temporal. Els resultats obtinguts superen l'estat de l'art amb un ús eficient dels paràmetres de la xarxa. Finalment, aquesta tesi també ofereix una revisió dels conceptes, dels recursos i de la literatura sobre tasques relacionades amb la detecció de música.
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Johnson, Sarah Anne. "Behavioural and Neuronal Correlates of Long-term Contextual Memory for Cocaine: Relevance to Craving and Relapse." Thesis, 2014. http://hdl.handle.net/1807/65673.
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Relapse is the single greatest barrier to recovery from addiction. Long-term memories for drug experience and associated contextual cues can provoke craving and resumption of drug use, particularly when a reminder of a highly charged context is encountered. In this thesis, three key questions related to the maintenance of long-term memory for drug-associated contexts are addressed: (1) Are Pavlovian conditioned associations between cocaine experience and the context in which it occurred maintained in long-term memory after extended periods of abstinence? (2) Are regions of the mesocorticolimbic circuitry, namely the nucleus accumbens and amygdala, differentially activated by retrieval of Pavlovian conditioned associations as time passes after cocaine experience? (3) Do neurons of the nucleus accumbens and amygdala show changes in dendritic architecture that reflect the impact of chronic cocaine exposure, which may underlie the maintenance of Pavlovian and/or instrumental drug-conditioned associations? Results confirm that Pavlovian conditioned memory for a cocaine-associated context is maintained in the long-term, becoming increasingly resilient over time. However, maintenance of these contextual associations is not accompanied by gross changes in dendritic architecture in neurons of the nucleus accumbens or amygdala within the timeframe examined. Nonetheless, these brain regions, along with the prefrontal cortex, are differentially activated by retrieval of Pavlovian conditioned associations after brief versus extended periods of abstinence. Together, these results emphasize a distinct contribution of Pavlovian memory processes, beyond instrumental and operant drug memory processes, in the long-term maintenance of addiction.
Books on the topic "Neurones de relais"
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Cohen, Marlene R., and John H. R. Maunsell. Neuronal Mechanisms of Spatial Attention in Visual Cerebral Cortex. Edited by Anna C. (Kia) Nobre and Sabine Kastner. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780199675111.013.007.
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Attention is associated with improved performance on perceptual tasks and changes in the way that neurons in the visual system respond to sensory stimuli. While we now have a greater understanding of the way different behavioural and stimulus conditions modulate the responses of neurons in different cortical areas, it has proven difficult to identify the neuronal mechanisms responsible for these changes and establish a strong link between attention-related modulation of sensory responses and changes in perception. Recent conceptual and technological advances have enabled progress and hold promise for the future. This chapter focuses on newly established links between attention-related modulation of visual responses and bottom-up sensory processing, how attention relates to interactions between neurons, insights from simultaneous recordings from groups of cells, and how this knowledge might lead to greater understanding of the link between the effects of attention on sensory neurons and perception.
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Dienel, Samuel J., and David A. Lewis. Cellular Mechanisms of Psychotic Disorders. Edited by Dennis S. Charney, Eric J. Nestler, Pamela Sklar, and Joseph D. Buxbaum. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190681425.003.0018.
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Cognitive dysfunction in schizophrenia, including disturbances in working memory, is a core feature of the illness and the best predictor of long-term functional outcome. Working memory relies on neural network oscillations in the prefrontal cortex. Gamma-aminobutyric acid (GABA) neurons in the prefrontal cortex, which are crucial for this oscillatory activity, exhibit a number of alterations in individuals diagnosed with schizophrenia. These GABA neuron disturbances may be secondary to upstream alterations in excitatory pyramidal cells in the prefrontal cortex. Together, these findings suggest both a neural substrate for working memory impairments in schizophrenia and therapeutic targets for improving functional outcomes in this patient population.
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Beninger, Richard J. Drug abuse and incentive learning. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198824091.003.0010.
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Drug abuse and incentive learning explains how abused drugs, including nicotine, ethanol, marijuana, amphetamine, cocaine, morphine, and heroin, produce conditioned place preference and are self-administered; dopamine receptor antagonists block these effects. Stimuli that become reliable predictors of drug reward produce burst firing in dopaminergic neurons, but the drug retains its ability to activate dopaminergic neurons. Thus, repeated drug users experience two activations of dopaminergic neurotransmission, one upon exposure to the conditioned stimuli signaling the drug and another upon taking the drug. This may lead to long-term neurobiological changes that contribute to withdrawal and addiction. Withdrawal can be remediated by abstinence but this does not reduce the conditioned incentive value of cues associated with drug taking; those cues can lead to relapse. Effective treatment will include detoxification and systematic exposure to drug taking-associated conditioned incentive stimuli in the absence of drug so that those stimuli lose their ability to control responses.
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Dietrich, W. Dalton. Physiologic Modulators of Neural Injury After Brain and Spinal Cord Injury. Edited by David L. Reich, Stephan Mayer, and Suzan Uysal. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190280253.003.0001.
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Brain and spinal cord injury are leading causes of death and long-term disability, producing diverse burdens for the affected individuals, their families, and society. Such injuries, including traumatic brain injury, stroke, subarachnoid hemorrhage, and spinal cord injury, have common patterns of neuronal cell vulnerability that are associated with a complex cascade of pathologic processes that trigger the propagation of tissue damage beyond the acute injury. Secondary injury mechanisms, including oxidative stress, edema formation, changes in cerebral blood flow and vessel reactivity, metabolic and blood–brain barrier disruption, and neuroinflammation, are therefore important therapeutic targets. Several key physiological parameters require monitoring and intensive management during various phases of treatment to ameliorate secondary injury mechanisms and potentially protect against further neuronal injury. This chapter reviews the core physiological targets in the management of brain and spinal cord injury and relates them to secondary injury mechanisms and outcomes.
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Saalmann, Yuri B., and Sabine Kastner. Neural Mechanisms of Spatial Attention in the Visual Thalamus. Edited by Anna C. (Kia) Nobre and Sabine Kastner. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780199675111.013.013.
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Neural mechanisms of selective attention route behaviourally relevant information through brain networks for detailed processing. These attention mechanisms are classically viewed as being solely implemented in the cortex, relegating the thalamus to a passive relay of sensory information. However, this passive view of the thalamus is being revised in light of recent studies supporting an important role for the thalamus in selective attention. Evidence suggests that the first-order thalamic nucleus, the lateral geniculate nucleus, regulates the visual information transmitted from the retina to visual cortex, while the higher-order thalamic nucleus, the pulvinar, regulates information transmission between visual cortical areas, according to attentional demands. This chapter discusses how modulation of thalamic responses, switching the response mode of thalamic neurons, and changes in neural synchrony across thalamo-cortical networks contribute to selective attention.
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Herman, James P. Limbic Pathways to Stress Control. Edited by Israel Liberzon and Kerry J. Ressler. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190215422.003.0008.
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Appropriate control of the HPA (hypothalamo-pituitary-adrenocortical axis) is required for adaptation to physiological and environmental challenges. Inadequate control is linked to numerous stress-related pathologies, including PTSD, highlighting its importance in linking physiological stress responses with behavioral coping strategies. This chapter highlights neurocircuit mechanisms underlying HPA axis adaptation and pathology. Control of the HPA stress response is mediated by the coordinated activity of numerous limbic brain regions, including the prefrontal cortex, hippocampus, and amygdala. In general, hippocampal output inhibits anticipatory HPA axis responses, whereas amygdala subnuclei participate in stress activation. The prefrontal cortex plays an important role in inhibition of context-dependent stress responses. These regions converge on subcortical structures that relay information to paraventricular nucleus corticotropin-releasing hormone neurons, controlling the magnitude and duration of HPA axis stress responses. The output of these neural networks determines the net effect on glucocorticoid secretion, both within the normal adaptive range and in pathological circumstances.
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Hawkes, Christopher H., Kapil D. Sethi, and Thomas R. Swift. Instant Neurological Diagnosis. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190930868.001.0001.
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Experienced neurologists work fast. They ask few questions, maybe perform a brief examination, and they come up with the right answer. Sometimes they do neither and their conclusions are accurate—but how do they do it? This book holds the answers. The book is divided into 14 chapters which, for the most part, focus on a particular neurologic condition, namely: demyelination, headache, epilepsy and sleep, myopathy and motor neuron disorders, movement disorders, stroke, peripheral neuropathy, cerebellar ataxia, and dementia. The remaining chapters are concerned with the clinician’s initial impressions (first encounters), cranial nerves, limbs and trunk, spinal lesions, and cerebrospinal fluid. At the end of each chapter is a summary of the salient points and a few key references. The final chapter relates to the fast neurological examination. Most diagnostic clues or “Handles” are illustrated by a table, figure, or video clip to reinforce a particular message, and the text is marked with Red Flags that the clinician must be alert for.
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Striedter, Georg F., and R. Glenn Northcutt. Brains Through Time. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780195125689.001.0001.
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Much is conserved in vertebrate evolution, but significant changes in the nervous system occurred at the origin of vertebrates and in most of the major vertebrate lineages. This book examines these innovations and relates them to evolutionary changes in other organ systems, animal behavior, and ecological conditions at the time. The resulting perspective clarifies what makes the major vertebrate lineages unique and helps explain their varying degrees of ecological success. One of the book’s major conclusions is that vertebrate nervous systems are more diverse than commonly assumed, at least among neurobiologists. Examples of important innovations include not only the emergence of novel brain regions, such as the cerebellum and neocortex, but also major changes in neuronal circuitry and functional organization. A second major conclusion is that many of the apparent similarities in vertebrate nervous systems resulted from convergent evolution, rather than inheritance from a common ancestor. For example, brain size and complexity increased numerous times, in many vertebrate lineages. In conjunction with these changes, olfactory inputs to the telencephalic pallium were reduced in several different lineages, and this reduction was associated with the emergence of pallial regions that process non-olfactory sensory inputs. These conclusions cast doubt on the widely held assumption that all vertebrate nervous systems are built according to a single, common plan. Instead, the book encourages readers to view both species similarities and differences as fundamental to a comprehensive understanding of nervous systems.
Book chapters on the topic "Neurones de relais"
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McKinley, Michael J., Peta Burns, Liana Colvill, Michelle Giles, Puspha Sinnayah, Nana Sunn, Brian J. Oldfield, and Richard S. Weisinger. "Neurons and neural pathways mediating the actions of circulating relaxin on the brain." In Relaxin 2000, 201–8. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-017-2877-5_29.
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Zieglgänsberger, W., C. Hauser, C. Wetzel, J. Putzke, G. R. Siggins, and R. Spanagel. "Actions of Acamprosate on Neurons of the Central Nervous System." In Acamprosate in Relapse Prevention of Alcoholism, 65–70. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-80193-8_4.
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Albright, Thomas D. "Neuroscienze per l’architettura." In La mente in architettura, 193–211. Florence: Firenze University Press, 2021. http://dx.doi.org/10.36253/978-88-5518-286-7.12.
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Discusses the Indian design treatise the Vaastu Veda in relation to visual neuroscience. Relates visual perception in architecture to functional organisation of the brain. Relates Hubel and Weisel’s orientation sensitivity to the sense of order and pleasure imparted by the regularity of colonnades and cable stay bridges. Suggests aspects of perception facilitated by neuronal architecture and the dynamic between familiarity and novelty, plasticity and visual attunement.
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Jones, Tanesha, Adriane B. Randolph, Kimberly Cortes, and Cassidy Terrell. "Using NeuroIS Tools to Understand How Individual Characteristics Relate to Cognitive Behaviors of Students." In Information Systems and Neuroscience, 181–84. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60073-0_20.
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Zieglgänsberger, Walter, and Marc L. Zeise. "Calcium-Diacetyl-Homotaurinate which Pre-Vents Relapse in Weaned Alcoholics Decreases the Action of Excitatory Amino Acids in Neo-Cortical Neurons of the Rat in Vitro." In Novel Pharmacological Interventions for Alcoholism, 337–41. New York, NY: Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4612-2878-3_41.
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Ball, Philip. "6. Delivering the message: molecular communication." In Molecules: A Very Short Introduction, 113–31. Oxford University Press, 2003. http://dx.doi.org/10.1093/actrade/9780192854308.003.0006.
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‘Delivering the message: molecular communication’ explains how molecules can enable communication between cells and in synthetic systems. Hormones are biological messengers which can have short–term or long–term effects. When released into the bloodstream, they travel to the target cells and bind with transmembrane proteins, initiating a signal transduction relay inside the cell. Neurons cells carry electrical action potentials along the nervous system. At neuronal synapses, chemical neurotransmitters carry signals across the synaptic cleft and transfer them to the next neuron along. Supramolecular chemists aim to utilise or mimic signal transduction pathways in a range of applications, from pharmaceuticals to mechanical olfaction.
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Dasgupta, Subrata. "Making (Bio)Logical Connections." In The Second Age of Computer Science. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190843861.003.0011.
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At first blush, computing and biology seem an odd couple, yet they formed a liaison of sorts from the very first years of the electronic digital computer. Following a seminal paper published in 1943 by neurophysiologist Warren McCulloch and mathematical logician Warren Pitts on a mathematical model of neuronal activity, John von Neumann of the Institute of Advanced Study, Princeton, presented at a symposium in 1948 a paper that compared the behaviors of computer circuits and neuronal circuits in the brain. The resulting publication was the fountainhead of what came to be called cellular automata in the 1960s. Von Neumann’s insight was the parallel between the abstraction of biological neurons (nerve cells) as natural binary (on–off) switches and the abstraction of physical computer circuit elements (at the time, relays and vacuum tubes) as artificial binary switches. His ambition was to unify the two and construct a formal universal theory. One remarkable aspect of von Neumann’s program was inspired by the biology: His universal automata must be able to self-reproduce. So his neuron-like automata must be both computational and constructive. In 1955, invited by Yale University to deliver the Silliman Lectures for 1956, von Neumann chose as his topic the relationship between the computer and the brain. He died before being able to deliver the lectures, but the unfinished manuscript was published by Yale University Press under the title The Computer and the Brain (1958). Von Neumann’s definitive writings on self-reproducing cellular automata, edited by his one-time collaborator Arthur Burks of the University of Michigan, was eventually published in 1966 as the book Theory of Self-Reproducing Automata. A possible structure of a von Neumann–style cellular automaton is depicted in Figure 7.1. It comprises a (finite or infinite) configuration of cells in which a cell can be in one of a finite set of states. The state of a cell at any time t is determined by its own state and those of its immediate neighbors in the preceding point of time t – 1, according to a state transition rule.
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Hämäläinen, Matti S. "Magnetoencephalography Source Estimation." In Fifty Years of Magnetoencephalography, 81–94. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190935689.003.0006.
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This chapter describes the source estimation approaches to magnetoencephalography (MEG) analysis. Both MEG and electroencephalography (EEG) are measures of ongoing neuronal activity, and are ultimately generated by the same sources: postsynaptic currents in groups of neurons which have a geometrical arrangement favoring currents with a uniform direction across nearby neurons. From the outset, the overarching theme of MEG analysis methods has been the desire to transform the signals measured by the MEG sensors outside the head into estimates of source activity. This problem is challenging because of the ill-posed nature of the electromagnetic inverse problem. However, thanks to being able to capitalize on appropriate physiological and anatomical constraints, several reliable and widely used source estimation methods have emerged. The chapter then identifies the forward modeling approaches needed to relate the signals in the source and sensor spaces, and characterizes two popular approaches to source estimation: the parametric dipole model and distributed source estimates. Until 50 years ago, electroencephalography (EEG) was the only noninvasive technique capable of directly measuring neuronal activity with a millisecond time resolution. However, with the birth of magnetoencephalography (MEG), functional brain activity can now be resolved with this time resolution at a new level of spatial detail. The use of MEG in practical studies began with the first real-time measurements in the beginning of 1970s. During the following decade, multichannel MEG systems were developed in parallel with both investigations of normal brain activity and clinical studies, especially in epileptic patients. The first whole-head MEG system with more than 100 channels was introduced in 1992. Up to now, such instruments have been delivered to researchers and clinicians worldwide. The overarching theme of MEG analysis methods has been from the outset the desire to transform the signals measured by the MEG sensors outside the head into estimates of source activity. This problem is challenging because of the ill-posed nature of the electromagnetic inverse problem. However, thanks to being able to capitalize on appropriate physiological and anatomical constraints, several reliable and widely used source estimation methods have emerged. This chapter starts by describing the overall characteristics of MEG, followed a general description of the source estimation problem. The chapter then discusses the forward modeling approaches needed to relate the signals in the source and sensor spaces, and finally characterizes two popular approaches to source estimation: the parametric dipole model and distributed source estimates.
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Winnicott, Donald W. "Paediatrics and Childhood Neurosis." In The Collected Works of D. W. Winnicott, 165–70. Oxford University Press, 2016. http://dx.doi.org/10.1093/med:psych/9780190271374.003.0034.
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In this essay, Winnicott discusses his view of neurosis as unconscious conflict, as anxiety arising from the violent conflicts between unconscious fantasy and the child’s inner reality. Neurosis relates to the instinctual life of the child. Fantasy is the imaginative elaboration of physical function whose arrival produces new problems at puberty. He discusses the roots of neurosis in the child’s earliest relationships and again emphasises the importance of paediatric training for child psychologists.
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Benarroch, Eduardo E. "Thalamus and Thalamocortical Interactions." In Neuroscience for Clinicians, edited by Eduardo E. Benarroch, 477–95. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780190948894.003.0026.
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The thalamus is critical for the routing of information and coordinating the forebrain activity responsible for arousal, attention, sensory processing, motor control, cognition, and behavior. It contains first-order relay nuclei that selectively project to modality-specific primary cortical sensory areas, high-order relay nuclei that participate in cortico-thalamo-cortical interactions for attention and high-level cognitive processing, motor nuclei that mediate influences of the cerebellum and basal ganglia, and intralaminar and midline nuclei that participate global cortical activation and control the function of the striatum. All these nuclei provide excitatory inputs to the cortex via thalamocortical neurons. Thalamocortical activity is controlled by GABAergic neurons of the reticular nucleus of the thalamus, which regulate the firing pattern of thalamocortical neurons during the sleep-wake cycle and in the setting of selective attention. Extrathalamic GABAergic, cholinergic, and monoaminergic inputs also strongly regulate the thalamic circuits in a behavioral state-dependent manner. Disruption in thalamocortical circuits is a major mechanism in disorders of impaired awareness such as absence and temporal lobe seizures and in the pathophysiology of cognitive disorders.
Conference papers on the topic "Neurones de relais"
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Agarwal, Rahul, Sabato Santaniello, and Sridevi V. Sarma. "Generalizing performance limitations of relay neurons: Application to Parkinson's disease." In 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2014. http://dx.doi.org/10.1109/embc.2014.6945134.
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Nicholson, Kristen J., and Beth A. Winkelstein. "The Duration of a Nerve Root Compression Modulates Evoked Neuronal Responses in a Rat Model of Painful Injury." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53082.
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The annual incidence for neck pain in the adult population is 30–50% [1]. The cervical nerve roots are at risk for mechanical injury due to impingement of surrounding structures which can result in pain and numbness [2]. During nerve root compression, an immediate, brief increase in spontaneous afferent activity and a gradual decrease in electrically evoked axonal conduction have been reported [3,4]. Although previous studies demonstrate that a transient cervical nerve root compression induces persistent behavioral sensitivity [5,6], it is not known how the tissue mechanics during loading modulate neuronal function or how they relate to the onset of pain. Therefore, the goal of this study was to quantify neuronal activity in the spinal cord as a function of the duration of applied compression by measuring both electrically-evoked and spontaneous afferent activity during a transient compression of the cervical nerve root in a rat model of pain [5,6].
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Yin, Huibing, Charles L. Cox, Prashant G. Mehta, and Uday V. Shanbhag. "Bifurcation analysis of a thalamic relay neuron model." In 2009 American Control Conference. IEEE, 2009. http://dx.doi.org/10.1109/acc.2009.5160443.
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Ravindra, Vikram, and Ananth Grama. "Characterizing Similarity of Visual Stimulus from Associated Neuronal Response." In Twenty-Ninth International Joint Conference on Artificial Intelligence and Seventeenth Pacific Rim International Conference on Artificial Intelligence {IJCAI-PRICAI-20}. California: International Joint Conferences on Artificial Intelligence Organization, 2020. http://dx.doi.org/10.24963/ijcai.2020/85.
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The problem of characterizing brain functions such as memory, perception, and processing of stimuli has received significant attention in neuroscience literature. These experiments rely on carefully calibrated, albeit complex inputs, to record brain response to signals. A major problem in analyzing brain response to common stimuli such as audio-visual input from videos (e.g., movies) or story narration through audio books, is that observed neuronal responses are due to combinations of ``pure'' factors, many of which may be latent. In this paper, we present a novel methodological framework for deconvolving the brain's response to mixed stimuli into its constituent responses to underlying pure factors. This framework, based on archetypal analysis, is applied to the analysis of imaging data from an adult cohort watching the BBC show, Sherlock. By focusing on visual stimulus, we show strong correlation between our observed deconvolved response and third-party textual video annotations -- demonstrating the significant power of our analyses techniques. Building on these results, we show that our techniques can be used to predict neuronal responses in new subjects (how other individuals react to Sherlock), as well as to new visual content (how individuals react to other videos with known annotations). This paper reports on the first study that relates video features with neuronal responses in a rigorous algorithmic and statistical framework based on deconvolution of observed mixed imaging signals using archetypal analysis.
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Agarwal, R., and S. V. Sarma. "An analytical study of relay neuron's reliability: Dependence on input and model parameters." In 2011 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2011. http://dx.doi.org/10.1109/iembs.2011.6090675.
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R Pendrill, Leslie, Jeanette Melin, and Stefan J Cano. "Metrological references for health care based on entropy." In 19th International Congress of Metrology (CIM2019), edited by Sandrine Gazal. Les Ulis, France: EDP Sciences, 2019. http://dx.doi.org/10.1051/metrology/201907001.
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Consistent diagnosis in healthcare relies, in part, on quality assurance of categorical observations, such as responses to ability tests and patient surveys. Linking classifications on such nominal and ordinal scales to decision-making involves a combination of logit transformations and novel entropy-based estimates of measurement information throughout the measurement process. This paper presents how entropy can explain and predict entity attributes (such as task difficulty), instrument ability and resolution, and measurement system response. Cognitive ability studies in the EMPIR NeuroMET project are taken as an example, showing how better understanding of both entity and measurement system attributes leads to more fit-for-purpose and better targeted treatment.
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Li, Huiyan, Fei Su, Jiang Wang, and Bin Deng. "A comparision of open-loop and closed-loop DBS to control the thalamic relay neuron's Parkinsonian state." In 2015 27th Chinese Control and Decision Conference (CCDC). IEEE, 2015. http://dx.doi.org/10.1109/ccdc.2015.7162631.
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Smith, Jenell R., Sarah M. Rothman, Paul A. Janmey, and Beth A. Winkelstein. "Spinal PAR1 RNA Levels Are Regulated by Mechanical and Inflammatory Cues in Painful Nerve Root Compression." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53084.
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Radicular pain can be caused by a disc herniation that can compress the spinal nerve roots as they exit the spinal canal [1]. Pain models in the rat mimic both the mechanical and chemical components of a disc herniation, either individually or in combination, and have demonstrated that the specific injury inputs (i.e. mechanics, inflammation) modulate the pain responses [2,3]. For both types of nerve root injuries, allodynia (i.e. pain) is elevated as early as 1 day after injury but its temporal responses vary over time according to the type of injury insult [3]. Painful nerve root injuries also induce a host of inflammatory cascades in the spinal cord that promote neuronal healing [2–4]. Although inflammatory responses have been shown to relate to the onset and maintenance of pain following injury, the specific biochemical processes and their relationship to inflammation and pain symptoms are not yet fully defined.
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Sun, X. M., Z. F. Cheng, S. L. Yang, and D. B. Chen. "Single-neuron Quasi-PID Control Method for Switching Power Amplifiers in Protective Relay Test Devices." In 4th International Conference on Information Technology and Management Innovation. Paris, France: Atlantis Press, 2015. http://dx.doi.org/10.2991/icitmi-15.2015.55.
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Oliveira, Felipe Paiva de, Caique Marques Costa Oliveira, Juciana Aparecida Nascimento Silva, Kézia Dos Santos Carvalho, and Sandra Trindade Fazio De Arecippo. "ACIDENTE VASCULAR CEREBRAL (AVC) EM CÃO DECORRENTE DE HEMANGIOMA: RELATO DE CASO." In I Congresso On-line Nacional de Clínica Veterinária de Pequenos Animais. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1854.
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Introdução: o acidente vascular cerebral (AVC) origina-se em virtude de lesões que acometem os vasos sanguíneos do cérebro e pode ser caracterizado em: AVC isquêmico e AVC hemorrágico. O AVC hemorrágico, tem menor incidência e está associado a ruptura vascular congênita, neoplasias cerebrais primárias ou secundárias, doenças inflamatórias de vasos e entre outras. Dentre as neoplasias primárias que podem acometer o parênquima cerebral, temos os hemangiomas, que podem ser classificados em cavernosos, arteriovenosos, venosos e capilares. O hemangioma cavernoso é formado por canais capilares largamente agrupados apenas por uma camada de células endoteliais, sem parênquima cerebral normal ou elementos de parede vascular. Os animais apresentam sinais clínicos que se relacionam com a localização da neoplasia e dentre estes temos mudança de comportamento, ataxia e crises convulsivas. Objetivos: com esta produção temos como objetivo relatar o caso de um acidente vascular cerebral em decorrência de um hemangioma. Material e métodos: foi encaminhado ao setor de anatomopatologia do curso de medicina veterinária do Centro Universitário Cesmac, um cão macho, da raça husky siberiano, com 4 anos de idade que, segundo o tutor, a um ano apresentava quadros de convulsão e veio a óbito na última crise convulsiva sem ter recebido nenhum atendimento veterinário. Foi realizado a necropsia do animal e fragmentos de órgãos foram colhidos, fixados em formol a 10%, processados para histologia em coloração rotineira de hematoxilina e eosina para subsequente visualização dos achados em microscópio óptico. Resultados: no exame macroscópico os principais achados foram, presença de intensa congestão em rins, pulmão, coração e fígado. Na abertura do crânio foi observado intensa congestão encefálica e uma área de hemorragia, subdural, localizada em lobo frontal. Histologicamente, essa área encéfalo continha moderada celularidade, bem delimitada, não encapsulada, composta por grandes espaços vasculares pavimentados por células endoteliais e preenchidos por eritrócitos, alguns contendo material fibrilar eosinofílico (fibrina). Em parênquima cerebral adjacente, havia esferoides axonais, astrócitos gemistócitos e cromatólise neuronal. Conclusão: os achados microscópicos foram consistentes com hemangioma cavernoso, primário em cérebro e necrose isquêmica aguda em tecido nervoso subjacente.