Suprachiasmatic Nucleus
Mostrando 13-24 de 89 artigos, teses e dissertações.
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13. Modulação dos genes de relógio Per1, Cry1b, Clock e da melanopsina por endotelina-1 em células embrionárias de Danio rerio / Modulation of clock genes Per1, Cry1b, Clock and of melanopsin by endothelin-1 in Danio rerio embryonic cells
Biological clocks are endogenous timekeepers that are present both in eukaryotic as in prokaryotic organisms. Different clocks have different periods, and those that have about 24h of oscillation are called circadian clocks. In mammals, the first identified circadian clock is located in the suprachiasmatic nucleus, in the hipothalamus. It is now well known t
Publicado em: 2007
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14. Serotonergic system - Interactions with the circadian timing system. / Sistema serotonérgico - relações com o sistema de temporização circadiano.
Componente essencial do sistema de temporização circadiano, o núcleo supraquiasmático (NSQ) possui três aferências principais: o trato retinohipotalâmico (TRH), o trato geniculohipotalâmico (TGH) e as terminações serotonérgicas da rafe. Suas células possuem oscilação circadiana autônoma que resultam na expressão rítmica dos chamados genes do
Publicado em: 2007
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15. "O núcleo supraquiasmático e o folheto intergeniculado do mocó (Kerodon rupestris): Projeções retinianas e caracterização imuno-histoquímica
In this study, two circadian related centres, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) were evaluated in respect to their cytoarchitecture, retinal afferents and chemical content of major cells and axon terminals with a tract tracer and immunohistochemical techniques in the rock cavy (Kerodon rupestris), a Brazilian caviidae ro
Publicado em: 2007
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16. Preservation of light signaling to the suprachiasmatic nucleus in vitamin A-deficient mice
To investigate the role of retinal-based pigments (opsins) in circadian photoreception in mice, animals mutated in plasma retinol binding protein were placed on a vitamin A-free diet and tested for photic induction of gene expression in the suprachiasmatic nucleus. After 10 months on the vitamin A-free diet, the majority of mice contained no detectable
The National Academy of Sciences.
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17. Persistence of circadian rhythmicity in a mammalian hypothalamic "island" containing the suprachiasmatic nucleus.
The experimental work described tested the prosposition that the suprachiasmatic nucleus of the hypothalamus is an autonomous circadian pacemaker. Simultaneous recording from two extracellular electrodes indicated neural (multiple unit) activity at two sites in the brain, one of which is in or near the suprachiasmatic nucleus and the other in one of many oth
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18. Neonatal suprachiasmatic nucleus ablation: absence of functional and morphological plasticity.
Neonatal ablation of the suprachiasmatic nucleus in the rat has two important consequences. First, the direct projection from the retina to the suprachiasmatic nucleus fails to develop and no other retinal projection to any hypothalamic nucleus is formed. Second, circadian rhythms in drinking and spontaneous locomotor activity to not appear in these rats whe
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19. Zinc modulation of a transient potassium current and histochemical localization of the metal in neurons of the suprachiasmatic nucleus.
The effect of Zn2+ on a voltage-dependent, transient potassium current (IA) in acutely dissociated neurons from the suprachiasmatic nucleus was studied with the whole-cell patch-clamp technique. At micromolar concentrations, Zn2+ markedly potentiated IA activated from a holding potential of -60 mV, which is the resting potential of these neurons. This potent
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20. Diurnal changes in sympathetic activity. Relation to food intake and to insulin injected into the ventromedial or suprachiasmatic nucleus.
The present study was designed to test whether there are diurnal changes in the firing rate of sympathetic nerves to brown adipose tissue and whether these diurnal rhythms influenced the response to insulin injected into the suprachiasmatic nucleus or ventromedial hypothalamic nucleus (VMH). Food intake was highest at the beginning of the dark period (1800-2
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21. An ultrastructural study of the rat's suprachiasmatic nucleus.
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22. Orexins, orexigenic hypothalamic peptides, interact with autonomic, neuroendocrine and neuroregulatory systems
We determined the immunohistochemical distributions of orexin-A and orexin-B, hypothalamic peptides that function in the regulation of feeding behavior and energy homeostasis. Orexin-A and -B neurons were restricted to the lateral and posterior hypothalamus, whereas both orexin-A and -B nerve fibers projected widely into the olfactory bulb, cerebral cortex,
The National Academy of Sciences.
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23. Ablation of suprachiasmatic nucleus alters timing of hibernation in ground squirrels.
Hibernation patterns were monitored continuously for 2.5 years in female squirrels that were neurologically intact or in which the hypothalamic suprachiasmatic nucleus (SCN) was completely ablated (SCNx). The number of hibernation bouts in SCNx squirrels increased by 159%, total hibernation time increased by 58%, and periodic arousals from hibernation were 4
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24. Two distinct oscillators in the rat suprachiasmatic nucleus in vitro.
In the rat suprachiasmatic nucleus slice culture, circadian rhythms in the release of arginine vasopressin and vasoactive intestinal polypeptide were measured simultaneously and longitudinally. The phase relationship between the two peptide rhythms was relatively constant in the culture without a treatment of antimitotic drugs but became diverse by an introd