Effects of postoperative environment on functional recovery after entorhinal cortex lesions in the rat

Abstract

Young rats (31 days old) sustained bilateral entorhinal cortex lesions and were then housed in different conditions (“enriched” or “impoverished”) to assess the contribution of the postoperative environment to recovery from the effects of the lesion. They were subsequently tested on spontaneous alternation and Hebb—Williams maze learning tasks. In both of these tasks, the performance of rats bearing entorhinal cortex lesions was inferior to that of sham-operated controls. Environmental enrichment improved performance only in sham-operated rats and this only at the level of initial errors in the Hebb—Williams task. There was no evidence for an interaction between lesion and environmental factors. It is suggested that the effects of differential rearing are dependent, in part at least, on the integrity and on the neural and perhaps glial organization of the entorhinal cortex.