Circadian rhythms of enzyme and running activity under ultradian lighting schedule.
Serotonin N-acetyltransferase activity in the pineal gland and running acitvity of rats were measured under an ultradian lighting schedule (light/dark 6:6). When rats were moved from a diurnal lighting condition to the ultradian conditions, N-acetyltransferase activity showed a circadian rhythm, increasing once a day. N-acetyltransferase activity in the pups born and raised under the ultradian lighting conditions also exhibited a circadian change, the phase of which coincided with that of their mothers. When pups were raised by a foster mother with an inverted rhythmic phase from that of the original mother, the phase of the rhythm in N-acetyltransferase activity of the pups synchronized with that of the foster mother. When pups were separated from their mothers for 12 h/day, the circadian increase of N-acetyltransferase activity appeared during the dark period when they were separated from their mothers. The circadian rhythms of running acitvity were in phase with those of N-acetyltransferase activity in the pineal gland.
D000123:Acetyltransferases / Q000032:analysis*; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002940:Circadian Rhythm; D003624:Darkness; D005247:Feeding Behavior; D005260:Female; D008027:Light; D008297:Male; D009043:Motor Activity; D010870:Pineal Gland / Q000201:enzymology*; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin; D000123:Acetyltransferases