PRESYNAPTIC AND POSTSYNAPTIC MECHANISMS OF INVOLVEMENT OF THE SEROTONERGIC SYSTEM IN CONDITIONED PASSIVE-AVOIDANCE RECALL IN RATS

Serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) content, MAO activity, and [H-3]-5-HT specific binding were examined in rat amygdal a at different stages of one-trial passive avoidance training. Seroton ergic changes were revealed only at the stage of the avoidance recall. The [H-3]-5-HT specific binding was decreased, MAO activity was incre ased and accompanied by enhanced 5-HIAA transport from serotonergic te rminals. No changes were revealed in 5-HT content. It is suggested tha t the retrieval processes in passive avoidance learning are mediated b y serotonergic system of the amygdala.