Environmental Enrichment Facilitates Amygdala Kindling but Reduces Kindling-Induced Fear in Male Rats.

Abstract

The purpose of this experiment was to determine the effect of prior environmental enrichment on the acquisition of kindling and the expression of kindling-induced fear. Sixty male rats were housed either in an enriched environment or in isolation, starting immediately after weaning. As adults, they were subjected to either 50 amygdala-kindling stimulations or sham stimulations, followed by testing in an unfamiliar open field. The kindled-enriched rats acquired the kindled state more quickly than did the kindled-isolated rats, but they also showed less fear in the open field than did the kindled-isolated rats. These results suggest that environmental enrichment has differential effects on kindling acquisition and its behavioral consequences.