Kunming Institute of Zoology, Chinese Academy of Sciences
Abstract
In the present experiment, Pavlovian fear conditioning was adopted to
study the effects of different early rearing environments on fear
conditioning in adult rats. Weaned rats were reared in three
manipulable environments (enriched, social and isolated conditions).
After 8 weeks, fear conditioning (characterized by percentage of
freezing) was observed and analyzed, and rats’ weight, locomoter
activity and foot-shock sensitivity were operated too. The results
showed that: (1) Compared with control group, the level of conditioned
fear was significantly increased in enriched group, but significantly
decreased in isolated group; (2) Enriched and isolated conditions
influenced rat’s weight significantly; (3) Different rearing
conditions have no effect on locomoter activity and foot-shock
sensitivity. These results indicated that early enriched condition
could improve the tone-evoked fear conditioning response, while
isolated condition impaired the response