Navegando por Palavras-chave "Paradoxical sleep"

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    Influence of long-term food restriction on sleep pattern in male rats
    (Elsevier B.V., 2005-09-28) Alvarenga, Tathiana Aparecida Fernandes [UNIFESP]; Andersen, Monica Levy [UNIFESP]; Papale, Ligia Assumpção [UNIFESP]; Antunes, Isabela B. [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The present purpose was to determine the effects of different schedules of long-term food restriction (FR) applied to rats from weaning to the 8th week. Rats were distributed into FR and ad libitum groups at weaning and fed at 7 am, at 7 pm, and finally, restricted rats fed ad libitum. the restricted rats started with 6 g/day and the food was increased by I g per week until reaching 15 g/day by adulthood. the rats were implanted with electrodes to record electrocorticogram/eletromyogram signals. Their wake-sleep cycles were monitored over 3 consecutive days (72 h of recording). the FR group fed at 7 am showed an increase in awake time, and decrease in slow wave sleep (SWS) and paradoxical sleep (PS) during the three light periods compared with the control recordings whereas in the dark periods, these sleep parameters were the opposite. the restricted group fed in the evening showed no statistical significances at diurnal periods; however, a significant decrease was observed in the dark recordings for awake time, but the SWS and PS were increased in relation to controls. the analysis of the 24-h period demonstrated that both FR groups presented increase in SWS time. After being FR, the rats were fed ad libitum and their sleep was monitored for 3 additional days. During the first dark recording, the decrease in awake time and increase in SWS were still present; however, as ad libitum food continued, these sleep parameters returned to control values, reestablishing the normal sleep pattern. These results suggest that dietary restriction, regardless to the feeding schedule, caused increase in total sleep time, during the active period. (c) 2005 Elsevier B.V. All rights reserved.
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    Participation of the cholinergic system in the ethanol-induced suppression of paradoxical sleep in rats
    (Associação Brasileira de Divulgação Científica, 2008-09-01) Papale, Ligia Assumpção [UNIFESP]; Andersen, Monica Levy [UNIFESP]; Perry, Juliana Cini [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Sleep disturbance is among the many consequences of ethanol abuse in both humans and rodents. Ethanol consumption can reduce REM or paradoxical sleep (PS) in humans and rats, respectively. The first aim of this study was to develop an animal model of ethanol-induced PS suppression. This model administered intragastrically (by gavage) to male Wistar rats (3 months old, 200-250 g) 0.5 to 3.5 g/kg ethanol. The 3.5 g/kg dose of ethanol suppressed the PS stage compared with the vehicle group (distilled water) during the first 2-h interval (0-2 h; 1.3 vs 10.2; P < 0.001). The second aim of this study was to investigate the mechanisms by which ethanol suppresses PS. We examined the effects of cholinergic drug pretreatment. The cholinergic system was chosen because of the involvement of cholinergic neurotransmitters in regulating the sleep-wake cycle. A second set of animals was pretreated with 2.5, 5.0, and 10 mg/kg pilocarpine (cholinergic agonist) or atropine (cholinergic antagonist). These drugs were administered 1 h prior to ethanol (3.5 g/kg) or vehicle. Treatment with atropine prior to vehicle or ethanol produced a statistically significant decrease in PS, whereas pilocarpine had no effect on minutes of PS. Although the mechanism by which ethanol induces PS suppression is not fully understood, these data suggest that the cholinergic system is not the only system involved in this interaction.
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    Sleep Deprivation Increases Mortality in Female Mice Bearing Ehrlich Ascitic Tumor
    (Karger, 2013-01-01) Maragno-Correa, Jussara Maria Ragonezzi [UNIFESP]; Patti, Camilla L. [UNIFESP]; Zanin, Karina A. [UNIFESP]; Wuo-Silva, Raphael [UNIFESP]; Ruiz, Francieli S. [UNIFESP]; Zager, Adriano; Sa-Nunes, Anderson; Tufik, Sergio [UNIFESP]; Andersen, Monica L. [UNIFESP]; Frussa-Filho, Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Objectives:Sleep deprivation is a growing public health hazard, yet it is still under-recognized. Sleep disorders and disruption of sleep patterns may compromise the immune function and adversely affect host resistance to infectious diseases. This is a particular risk in cancer patients, who report a high frequency of sleep disturbances. the present study investigated the effects of sleep deprivation on the development of Ehrlich ascitic tumors (EAT) in female BALB/c mice. Our study also evaluated whether EAT would induce alterations in sleep pattern. Spleen lymphocyte cell populations and mortality were also quantified. Methods: Female BALB/c mice were intraperitoneally inoculated with EAT cells. Immediately after the inoculation procedure, animals were sleep deprived for 72 h. Ten or 15 days after inoculation, the number of tumoral cells was quantified and the lymphocytic cell population in the spleen was characterized by flow cytometry. in addition, the effect of sleep deprivation on EAT-induced mortality was quantified and the influence of EAT on sleep patterns was determined. Results: Sleep deprivation did not potentiate EAT growth, but it significantly increased mortality. Additionally, both EAT and sleep deprivation decreased frequencies of splenic CD4+, CD8+ and CD19+ cells. With respect to sleep patterns, EAT significantly enhanced paradoxical sleep time. Conclusions: Although sleep deprivation did not potentiate EAT growth, it decreased the survival of female tumor-bearing mice. Copyright (c) 2013 S. Karger AG, Basel