THE EFFECTS OF ISOLATION-REARING OF RATS ON BEHAVIORAL-RESPONSES TO FOOD AND ENVIRONMENTAL NOVELTY

Isolation-reared rats exhibited enhanced behavioural responses to nove lty, but only some aspects of such behavior was affected. In Experimen t 1, environmental neophobia was enhanced but food neophobia was dimin ished in isolation-reared rats compared to socially reared rats. Howev er, in Experiment 2, when subjects were not handled extensively prior to testing. no differences in behavioural responses to environmental o r food novelty in an open-field were observed between rearing groups. The difference between these experiments was hypothesized to be the re sult of ceiling effects produced by increased anxiety or arousal in ex periment 2 in which the animals had nor been extensively handled. In s ummary, in these experiments anticipatory responses to novelty were al terred by isolation-rearing but the behavioural expression of this inc reased sensitivity was determined by intrinsic aversive/rewarding or a rousing qualities of novel environments and novel foods. (C) 1997 Else vier Science Inc.