Ontogenetic changes in the modulation of taste aversion learning by home environmental cues in rats.

Abstract

Experiments [8] using 611 rats as subjects were conducted to define and analyze an age-related phenomenon of conditioned taste aversion. When consumption of sucrose solution was followed by LiCl-induced illness in the animals'' home, acquisition of the aversion to sucrose solution was retarded in preweanling (18 day old) rats. This effect was not found in adults or in slightly older (21 day old) rats. Place of testing had no effect in the younger 2 age-groups, but in adults manifestation of the acquired aversion was retarded when they were tested in the home. There was no interaction between place of conditioning and testing for any age. The locus of the environmental influence on conditioning in preweanling rats was the place of tasting rather than place of illness, retention interval or testing. The effect was invariant under minor variations in familiarization of the animal with the non-home environment. The home environment may have a significant influence on learning and conditioning in the immature rat.