Food motivation in rats of different ages

Abstract

In this study, we attempted to compare food motivation in Brown-Norway rats of three different ages (8, 14, and 26 months old) under two different levels of food deprivation by measuring running speed in a runway. Food motivation was also assessed in a progressive ratio schedule of reinforcement in an operant chamber at one level of deprivation. Compared with the adult and middle-aged rats, the old rats had a slower running speed in the runway and made fewer leverpresses in the progressive ratio test. It was suggested that both age and weight affected the level of food motivation. A differential food deprivation technique (i.e., an age-related increase in the percentage of body weight reduction) may possibly be a way to reduce differences in levels of food motivation in rats of different ages. © 1993, Psychonomic Society, Inc.. All rights reserved.