Entrainment in calorie-restricted mice: Conflicting zeitgebers and free- running conditions

Etienne Challet*, Leah C. Solberg, Fred W. Turek

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

85 Scopus citations

Abstract

Phaseshifting effects of timed calorie restriction were investigated in mice during exposure to a 12:12-h light-dark cycle. Food-anticipatory activity (FAA), the output of a food-entrainable pacemaker, was expressed before the time of feeding whether mice received daily hypocaloric food (3.3 g of chow/day) or normocaloric food (5 g of chow/day) at zeitgeber time (ZT) 2 (ZT12 = lights off). Subsequently, mice were placed in constant darkness and fed ad libitum. The onset of the nocturnal period of locomotor activity was phase advanced by I h in calorie-restricted mice compared with normocalorie-fed controls. The phase advance still occurred when FAA was prevented by restraining calorie-restricted mice. Giving hypocaloric food at ZT2, ZT10, ZT14, or ZT22 phase advanced the nocturnal pattern of activity by 1, 3, 1, and 1 h, respectively. After transfer to constant darkness, FAA free ran in parallel with the normal nocturnal period of locomotor activity. A light pulse during the early subjective night phase delayed both components. These results indicate that 1) timed calorie restriction under a light-dark cycle can phase advance the light-entrainable pacemaker with a phase- dependent magnitude, 2) FAA feedback is not crucial for the observed phase advance, and 3) the light-entrainable pacemaker may control the period of the food-entrainable pacemaker in mice fed ad libitum.

Original languageEnglish (US)
Pages (from-to)R1751-R1761
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume274
Issue number6 43-6
DOIs
StatePublished - 1998

Keywords

  • Circadian rhythm
  • Food synchronization
  • Food-anticipatory activity
  • Suprachiasmatic nucleus

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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