Daily restricted feeding rescues a rhythm of period2 expression in the arrhythmic suprachiasmatic nucleus.
Second only to light, daily restricted feeding schedules can entrain circadian rhythms in mammals [Neurosci Biobehav Rev 4 (1980) 119; J Biol Rhythms 17 (2002) 284]. Contrary to light, however, such feeding schedules have been found not to affect the master circadian clock in the suprachiasmatic nucleus (SCN) [Genes Dev 14 (2000) 2950; Eur J Neurosci 13 (2001) 1190]. Here, we show that in rats that are arrhythmic as a consequence of prolonged housing in constant light, a daily restricted feeding schedule not only restores behavioral rhythmicity, as previously shown [Physiol Behav 53 (1993) 509], but in addition, induces a rhythm of the clock protein, Period2 in the SCN. These findings challenge the idea that the SCN is invulnerable to feeding schedules and call for a reevaluation of the role of the SCN clock in the circadian effects of such schedules.
Lamont
E W
EW
Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Room SP244, 7141 Sherbrooke Street West, Montreal, Quebec, Canada H4B 1R6.
Diaz
L Renteria
LR
Barry-Shaw
J
J
Stewart
J
J
Amir
S
S
D000704:Analysis of Variance; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000378:metabolism*; D001522:Behavior, Animal; D002940:Circadian Rhythm / Q000502:physiology*; D005136:Eye Proteins / Q000378:metabolism*; D005247:Feeding Behavior / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009043:Motor Activity / Q000502:physiology; D017440:Photoperiod; D051381:Rats; D017208:Rats, Wistar; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*; D013997:Time Factors
D005136:Eye Proteins