Navegando por Palavras-chave "Sleep-wake cycle"
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- ItemAcesso aberto (Open Access)Caracterização do padrão do ciclo vigília-sono, avaliado pela actimetria, em uma amostra da população da cidade de São Paulo(Universidade Federal de São Paulo (UNIFESP), 2010-07-28) Guzzo, Lia Alves Simões Matuzaki [UNIFESP]; Bittencourt, Lia Rita Azeredo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: There are few studies evaluating the characteristics of the sleep-wake cycle (SWC) patterns in the general population. The aims of this study was to evaluate the SWC in a sample of the São Paulo city population; to assess the characteristics of SWC according to the chronotype; and to compare the polysomnography (PSG) and actimetry simultaneously recorded. Methods: Volunteers were selected from a population based study (São Paulo Epidemiologic Sleep Study), stratified by gender, age (20-80 years-old) and socioeconomic status. SWC was measured for at least three consecutive days using actimetry (Actwach-64®) and sleep diary. Social-demographic, health and sleep habits and complaints data were gathered from the questionnaires and a full-night PSG was performed. Results: Out of a sample of 1101 volunteers selected to represent the adult population of São Paulo, 359 volunteers wore the actimetry properly and 60% were women. The mean age was 43 ± 14 years and the mean total sleep time (TST) was 365 ± 57 minutes. The most of the participants presented monophasic pattern of sleep (92%), 7% had biphasic pattern and 1% had poliphasic pattern. According to a Two-step Cluster analysis, volunteers were included into three groups: morningness (61%), composed of individuals that had the sleep onset around 10:00 PM and TST was 374 ± 52 minutes; eveningness (32%), composed of individuals that had the sleep onset at 2:00 AM and TST was 349 ± 66 minutes; and the other group (7%), who had no defined sleep onset time and TST was 362 ± 58 minutes. We observed a moderate correlation between PSG and actimetry for TST (r=0.7) (p<0.001), and a weak correlation for sleep efficiency (r=0.4) (p<0.001), sleep latency (r=0.2) (p<0,001) and wake after sleep onset (r=0.3) (p<0.001). Conclusions: Our data suggest that the evaluated population presented mostly monophasic sleep pattern. Based on the selection of the variables (sleep onset time, TST, sleep efficiency and sleep latency) the actimetry was reliable to establish the profile of the population according to chronotype. Although differences between the actimetry and the PSG have been observed, the results support the use of actimetry to evaluate the sleep episodes.
- ItemAcesso aberto (Open Access)Sleep pattern and learning in knockdown mice with reduced cholinergic neurotransmission(Associação Brasileira de Divulgação Científica, 2013-01-01) Queiroz, Claudio Marcos [UNIFESP]; Tiba, Paula Ayko; Moreira, Karin Monteiro [UNIFESP]; Guidine, Patrícia Alves Maia; Rezende, Gustavo H S; Moraes, Márcio Flávio Dutra; Prado, Marco Antônio Máximo; Prado, Vânia Ferreira; Tufik, Sergio [UNIFESP]; Mello, Luiz Eugenio Araujo de Moraes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal do Rio Grande do Norte Instituto do Cerebro; Universidade Federal do ABC Computacao e Cognicao Centro de Matematica; Universidade Federal de Minas Gerais Departamento de Fisiologia e Biofisica Nucleo de Neurociencias; University of Western Ontario Department of Physiology and Pharmacology and Department of Anatomy and Cell Biology Robarts Research InstituteImpaired cholinergic neurotransmission can affect memory formation and influence sleep-wake cycles (SWC). In the present study, we describe the SWC in mice with a deficient vesicular acetylcholine transporter (VAChT) system, previously characterized as presenting reduced acetylcholine release and cognitive and behavioral dysfunctions. Continuous, chronic ECoG and EMG recordings were used to evaluate the SWC pattern during light and dark phases in VAChT knockdown heterozygous (VAChT-KDHET, n=7) and wild-type (WT, n=7) mice. SWC were evaluated for sleep efficiency, total amount and mean duration of slow-wave, intermediate and paradoxical sleep, as well as the number of awakenings from sleep. After recording SWC, contextual fear-conditioning tests were used as an acetylcholine-dependent learning paradigm. The results showed that sleep efficiency in VAChT-KDHET animals was similar to that of WT mice, but that the SWC was more fragmented. Fragmentation was characterized by an increase in the number of awakenings, mainly during intermediate sleep. VAChT-KDHET animals performed poorly in the contextual fear-conditioning paradigm (mean freezing time: 34.4±3.1 and 44.5±3.3 s for WT and VAChT-KDHET animals, respectively), which was followed by a 45% reduction in the number of paradoxical sleep episodes after the training session. Taken together, the results show that reduced cholinergic transmission led to sleep fragmentation and learning impairment. We discuss the results on the basis of cholinergic plasticity and its relevance to sleep homeostasis. We suggest that VAChT-KDHET mice could be a useful model to test cholinergic drugs used to treat sleep dysfunction in neurodegenerative disorders.
- ItemSomente MetadadadosThe sleep-wake cycle in adult rats following pilocarpine-induced temporal lobe epilepsy(Elsevier B.V., 2010-03-01) Matos, Gabriela; Tsai, Rodrigo; Baldo, Marcus Vinicius; Castro, Isac de [UNIFESP]; Sameshima, Koichi; Valle, Angela Cristina; Universidade de São Paulo (USP); Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP)The relationship between sleep and epilepsy is both complex and clinically significant. Temporal lobe epilepsy (TLE) influences sleep architecture, while sleep plays an important role in facilitating and/or inhibiting possible epileptic seizures. the pilocarpine experimental model reproduces several features of human temporal lobe epilepsy and is one of the most widely used models in basic research. the aim of the present study was to characterize, behaviorally and electrophysiologically, the phases of sleep-wake cycles (SWC) in male rats with pilocarpine-induced epilepsy. Epileptic rats presented spikes in all phases of the SWC as well as atypical cortical synchronization during attentive wakefulness and paradoxical sleep. the architecture of the sleep-wake phases was altered in epileptic rats, as was the integrity of the SWC. Because our findings reproduce many relevant features observed in patients with epilepsy, this model is suitable to study sleep dysfunction in epilepsy. (C) 2009 Elsevier Inc. All rights reserved.