working for food shifts nocturnal mouse activity into the day为食物夜间鼠标活动转变成工作.pdfVIP

Working for Food Shifts Nocturnal Mouse Activity into the Day Roelof A. Hut*., Violetta Pilorz., Ate S. Boerema, Arjen M. Strijkstra, Serge Daan Chronobiology Unit, Center for Behavior and Neurosciences, University of Groningen, Groningen, The Netherlands Abstract Nocturnal rodents show diurnal food anticipatory activity when food access is restricted to a few hours in daytime. Timed food access also results in reduced food intake, but the role of food intake in circadian organization per se has not been described. By simulating natural food shortage in mice that work for food we show that reduced food intake alone shifts the activity phase from the night into the day and eventually causes nocturnal torpor (natural hypothermia). Release into continuous darkness with ad libitum food, elicits immediate reversal of activity to the previous nocturnal phase, indicating that the classical circadian pacemaker maintained its phase to the light-dark cycle. This flexibility in behavioral timing would allow mice to exploit the diurnal temporal niche while minimizing energy expenditure under poor feeding conditions in nature. This study reveals an intimate link between metabolism and mammalian circadian organization. Citation: Hut RA, Pilorz V, Boerema AS, Strijkstra AM, Daan S (2011) Working for Food Shifts Nocturnal Mouse Activity into the Day. PLoS ONE 6(3): e17527. doi:10.1371/journal.pone.0017527 Editor: Shin Yamazaki, Vanderbilt University, United States of America Received December 9, 2010; Accepted February 3, 2011; Published March 30, 2011 Copyright: 2011 Hut, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The study was supported by EC-FP6 Integrated Project 018