Effects of photoperiod on daily locomotor activity, energy expenditure, and feeding behavior in a seasonal mammal.

ABSTRACT: The objective of this study was to determine whether the previously observed effects of photoperiod on body weight in Siberian hamsters were due to changes in the daily patterns of locomotor activity, energy expenditure, and/or feeding behavior. Adult males were monitored through a seasonal cycle using an automated comprehensive laboratory animal monitoring system (CLAMS). Exposure to a short-day photoperiod (SD; 8:16-h light-dark cycle) induced a significant decline in body weight, and oxygen consumption (Vo(2)), carbon dioxide production (Vco(2)), and heat production all decreased reaching a nadir by 16 wk of SD. Clear daily rhythms in locomotor activity, Vo(2), and Vco(2) were observed at the start of the study, but these all progressively diminished after prolonged exposure to SD. Rhyt

SUBMITTER: Warner A 

PROVIDER: S-EPMC2867510 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature