Early environmental influences on conditioned and unconditioned ingestional and locomotor behaviors.

For 34-44 days after weaning one group of rats was raised in a socially enriched environment, whereas another group was raised in isolated individual cages without handling. Following this differential rearing subjects were tested for ingestional neophobia and its attenuation, enhancement of ingestional neophobia by aversive drug administration, taste-aversion learning and extinction, open-field activity, and passive shock-avoidance learning. Although the differential rearing influenced open-field activity and shock-avoidance this manipulation did not have a significant effect on the various measures of conditioned and unconditioned ingestional behaviors. The results provide further evidence for the distinctiveness of gustatory-visceral and telereceptor-cutaneous sensory systems.