Entrainment of mouse peripheral circadian clocks to <24?h feeding/fasting cycles under 24?h light/dark conditions.

ABSTRACT: The circadian clock system in peripheral tissues can endogenously oscillate and is entrained by the light-dark and fasting-feeding cycles in mammals. Although the system's range of entrainment to light-dark cycles with a non-24?h (<24?h) interval has been studied, the range of entrainment to fasting-feeding cycles with shorter periods (<24?h) has not been investigated in peripheral molecular clocks. In the present study, we measured this range by monitoring the mouse peripheral PER2::LUCIFERASE rhythm in vivo at different periods under each feeding cycle (Tau (T)?=?15-24?h) under normal light-dark conditions. Peripheral clocks could be entrained to the feeding cycle with T?=?22-24?h, but not to that with T?=?15-21?h. Under the feeding cycle with T?=?15-18?h, the peripheral clocks oscillated at near the 24-h period, suggesting that they were entrained to the light-dark cycle. Thus, for the first time, we demonstrated the range of entrainment to the non-24?h feeding cycle, and that the circadian range (T?=?22-24?h) of feeding stimulus is necessary for peripheral molecular clock entrainment under light-dark cycles.

SUBMITTER: Hamaguchi Y 

PROVIDER: S-EPMC4585804 | biostudies-other | 2015

REPOSITORIES: biostudies-other