TY - JOUR
T1 - Waking and sleeping in the rat made obese through a high-fat hypercaloric diet
AU - Luppi, Marco
AU - Cerri, Matteo
AU - Martelli, Davide
AU - Tupone, Domenico
AU - Del Vecchio, Flavia
AU - Di Cristoforo, Alessia
AU - Perez, Emanuele
AU - Zamboni, Giovanni
AU - Amici, Roberto
N1 - Funding Information:
This work has been supported by the Ministero dell’Università e della Ricerca Scientifica (MIUR), Italy, (PRIN 2009, Project 2009SPTHRK) and by the University of Bologna (University Strategic Project 2006). The authors wish to thank Dr. Silvia Laudadio for technical help and Ms Melissa Stott for reviewing the English.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Sleep restriction leads to metabolism dysregulation and to weight gain, which is apparently the consequence of an excessive caloric intake. On the other hand, obesity is associated with excessive daytime sleepiness in humans and promotes sleep in different rodent models of obesity. Since no consistent data on the wake-sleep (WS) pattern in diet-induced obesity rats are available, in the present study the effects on the WS cycle of the prolonged delivery of a high-fat hypercaloric (HC) diet leading to obesity were studied in Sprague-Dawley rats. The main findings are that animals kept under a HC diet for either four or eight weeks showed an overall decrease of time spent in wakefulness (Wake) and a clear Wake fragmentation when compared to animals kept under a normocaloric diet. The development of obesity was also accompanied with the occurrence of a larger daily amount of REM sleep (REMS). However, the capacity of HC animals to respond to a "Continuous darkness" exposure condition (obtained by extending the Dark period of the Light-Dark cycle to the following Light period) with an increase of Sequential REMS was dampened. The results of the present study indicate that if, on one hand, sleep curtailment promotes an excess of energy accumulation; on the other hand an over-exceeding energy accumulation depresses Wake. Thus, processes underlying energy homeostasis possibly interact with those underlying WS behavior, in order to optimize energy storage.
AB - Sleep restriction leads to metabolism dysregulation and to weight gain, which is apparently the consequence of an excessive caloric intake. On the other hand, obesity is associated with excessive daytime sleepiness in humans and promotes sleep in different rodent models of obesity. Since no consistent data on the wake-sleep (WS) pattern in diet-induced obesity rats are available, in the present study the effects on the WS cycle of the prolonged delivery of a high-fat hypercaloric (HC) diet leading to obesity were studied in Sprague-Dawley rats. The main findings are that animals kept under a HC diet for either four or eight weeks showed an overall decrease of time spent in wakefulness (Wake) and a clear Wake fragmentation when compared to animals kept under a normocaloric diet. The development of obesity was also accompanied with the occurrence of a larger daily amount of REM sleep (REMS). However, the capacity of HC animals to respond to a "Continuous darkness" exposure condition (obtained by extending the Dark period of the Light-Dark cycle to the following Light period) with an increase of Sequential REMS was dampened. The results of the present study indicate that if, on one hand, sleep curtailment promotes an excess of energy accumulation; on the other hand an over-exceeding energy accumulation depresses Wake. Thus, processes underlying energy homeostasis possibly interact with those underlying WS behavior, in order to optimize energy storage.
KW - Continuous darkness
KW - High-fat hypercaloric diet
KW - Obesity
KW - REM sleep
KW - Wake-sleep cycle
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U2 - 10.1016/j.bbr.2013.10.014
DO - 10.1016/j.bbr.2013.10.014
M3 - Article
C2 - 24149066
AN - SCOPUS:84887163824
SN - 0166-4328
VL - 258
SP - 145
EP - 152
JO - Behavioural Brain Research
JF - Behavioural Brain Research
ER -