The Rat's Adjustment to Repeated Exposure to 72-Hour Food Deprivation

Abstract

18 male albino rats were exposed to repeated cycles of 72-hr. food deprivation and 120 hr. of recovery. Over successive recovery periods Ss exhibited increases in food intake, decreases in wheel running, and decreases in the amount of recovery time required to regain and surpass pre-deprivation body-weight levels. Increases in activity occurred during 72-hr. deprivation and were found to show an increase over successive deprivations. In a second phase of the experiment the response to 72-hr. deprivation with increases in wheel running was found to be greater for rats permitted to run during recovery than for rats not permitted to run during recovery. These findings suggested that the response to 72-hr. deprivation with increases in activity is determined in part by a previous history of opportunity for reinforcement of the wheel-running response by ingestion.