Circadian Timing System
Mostrando 1-12 de 31 artigos, teses e dissertações.
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1. Serotonin and circadian rhythms
All mammal behaviors and functions exhibit synchronization with environmental rhythms. This is accomplished through an internal mechanism that generates and modulates biological rhythms. The circadian timing system, responsible for this process, is formed by connected neural structures. Pathways receive and transmit environmental cues to the central oscillat
Psychology & Neuroscience. Publicado em: 2010-12
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2. A simple model for circadian timing by mammals
Circadian timing is structured in such a way as to receive information from the external and internal environments, and its function is the timing organization of the physiological and behavioral processes in a circadian pattern. In mammals, the circadian timing system consists of a group of structures, which includes the suprachiasmatic nucleus (SCN), the i
Brazilian Journal of Medical and Biological Research. Publicado em: 2009-01
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3. Organização temporal em processos de condicionamento classico aversivo e na expressão da proteina Zenk no hipocampo de pombos (C. livia) / Temporal organization of classical aversive conditioning processes and expression of Zenk protein in the hippocampus of pigeons (C. livia)
Part of the knowledge about the mechanisms and neural basis of learning, memory and amnesia is based on the investigation of neural correlates of the behavior of non human animals in aversive situations. Moreover, many studies suggest that these behavioral processes are affected by the circadian timing system. The procedures of classical aversive conditionin
Publicado em: 2009
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4. A Zona Incerta no sagüi (Callithrix jacchus): Análise Citoarquitetônica, Neuroquímica e Projeção Retiniana
The retinal projections in mammals usually reach, classically, three major functional systems: the primary visual system, the accessory optic system, and the circadian timing system. But the retinal projections also reach areas classically considered non-visual, one of which groups the neurons of the zona incerta (ZI), target this study. The primary visual s
Publicado em: 2008
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5. Cytoarchitectural and immunohistochemical analysis of the visual system of tuffed capuchin (Cebus apella). / Análise citoarquitetônica e imunoistoquímica de estruturas do sistema visual de macacos-prego (Cebus apella)
O estudo do sistema visual de macacos-prego representa importante questão devido ao aspecto evolutivo que a espécie apresenta. Foram utilizados cinco macacos-prego, 2 kg. Foi efetuda injeção intra-ocular de 100 ml de solução aquosa de toxina colérica subunidade B (CTb) a 1%, sendo a perfusão realizada 15 dias após a injeção int
Publicado em: 2008
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6. Caracterização do ritmo de atividade motora durante a puberdade em sagüis (Callithrix jacchus) sob condições semi-naturais
Most of ontogenetic studies on circadian timing system have been developed on infants, adults and elderly. The puberty has not been a stage of life few studied, except for researches in human adolescents, that presents phase delay in sleep-wake cycle. However, few studies have focused on the basis of this circadian change due to methodological diffic
Publicado em: 2008
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7. Efeitos de vocalizações de co-específicos e do escuro sobre o ritmo circadiano da atividade motora em sagüis (Callithrix jacchus)
The principal zeitgeber for most of species is the light-dark photocycle (LD), though other environment factors as food availability, temperature and social cues may act. Daily adjustment of the circadian pacemaker may result from integration of environmental photic and non-photic cues with homeostatic cues. Characterization of non-photic effects on circadia
Publicado em: 2007
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8. 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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9. Influência da auto seleção à luz no ritmo circadiano de atividade motora em Callithrix Jacchus / The influence of self-selection of light on motor activity circadian rhythm in Callithrix jacchus
Marmosets, Callithrix jacchus, are strictly diurnal animals. The motor activity rhythmicity is generated by the circadian timing system and is modulated by environmental factors, mainly by photic stimuli that compose the light-dark cycle. Photic stimuli can reset the biological oscilators changing activity motor pattern, by a mechanism called entrainment. Ot
Publicado em: 2006
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10. Mathematical model of the circadian timing system / Modelo matemático do sistema de temporização biológica circadiana
Both the experimental evidences of generation of biological circadian rhythms and the results of investigation about the mechanisms of synchronization between the circadian rhythms with the external cycles of 24-hour period provided material for the development of important assumptions about the characteristics of the circadian timing system. Inside this sce
Publicado em: 2004
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11. Independence of Circadian Timing from Cell Division in Cyanobacteria
In the cyanobacterium Synechococcus elongatus, cell division is regulated by a circadian clock. Deletion of the circadian clock gene, kaiC, abolishes rhythms of gene expression and cell division timing. Overexpression of the ftsZ gene halted cell division but not growth, causing cells to grow as filaments without dividing. The nondividing filamentous cells s
American Society for Microbiology.
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12. Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure.
1. Both the timing of behavioural events (activity, sleep and social interactions) and the environmental light-dark cycle have been reported to contribute to entrainment of human circadian rhythms to the 24 h day. Yet, the relative contribution of those putative behavioural synchronizers to that of light exposure remains unclear. 2. To investigate this, we i