Navegando por Palavras-chave "spillage"

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    A reassessment of the hyperphagia/weight-loss paradox during sleep deprivation
    (Amer Academy Sleep Medicine, 2006-09-01) Martins, Paulo J. F. [UNIFESP]; D'Almeida, Vânia [UNIFESP]; Nobrega, Jose N.; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Ctr Addict & Mental Hlth
    Study Objectives: Sleep deprivation is a well-known paradigm to investigate the deleterious effects of prolonged wakefulness. Previous studies have shown that, during sleep deprivation, rats are hyperphagic but, paradoxically, lose body weight. This phenomenon has been attributed to increased metabolism. However, most previous studies have failed to account for food spillage, which may be considerable during sleep deprivation.Design: In the present study, we revisited the issue of feeding changes in sleep-deprived rats and introduced different procedures to allow accurate estimation of food spillage prior to, during, and after 120 hours of sleep deprivation by a single platform technique.Setting: Animal Sleep Research Laboratory, Psychobiology Department, Universidade Federal de Sao Paulo, Brazil.Measurements and Results: The main finding was that, once corrected for spillage, food intake was not significantly increased during sleep deprivation. Increases in food removed from feeders were accompanied by proportional increases in food spillage, resulting in no net changes in food intake. Further, weight loss did occur during the sleep-deprivation period, especially in the first 24 hours, and it was actually explained by a reduction in food intake.Conclusion: The hyperphagia/weight-loss paradox previously seen during prolonged sleep deprivation does not necessarily occur with shorter periods of deprivation. Although we found no evidence of hyperphagia for up to 5 days of sleep deprivation in chow-fed rats, our data suggest that an impairment in the ability to increase food intake in response to increased energy expenditure contributes to the energy deficit during sleep deprivation in rats.
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    Sleep deprivation-induced gnawing - relationship to changes in feeding behavior in rats
    (Elsevier B.V., 2008-01-28) Martins, P. J. F. [UNIFESP]; Nobrega, J. N.; Tufik, S. [UNIFESP]; D'Almeida, V. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Ctr Addict & Mental Hlth
    We have recently reported that food spillage increases during sleep deprivation in rats, which may lead to an overestimation of food intake in this condition. the objective of this study was to verify whether sleep deprivation induces an increase in gnawing behavior that could account for increased food spillage and apparent increase in food intake. We introduced wood blocks as objects for gnawing and determined the effects of their availability on food consumption and food spillage during sleep deprivation. Wood block availability reduced the amount of food removed from hoppers and decreased the amount of food spilled. However, weight loss still occurred during the sleep deprivation period, especially in the first 24 h, and it was related to a reduction in food intake. Sleep deprivation causes an increase in stereotyped gnawing behavior which largely accounts for increased food spillage observed during deprivation. Specifically, the observed increase in food removed from feeders seems to be due to an increase in gnawing and not to increased hunger. However, even when appropriately corrected for spillage, food intake decreased in the first 24 h of sleep deprivation, which accounted for most of the body weight loss seen during the 96 h of sleep deprivation. (C) 2007 Elsevier Inc. All rights reserved.