Pre- 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 amygdala at different stages of one-trial passive avoidance training. Serotonergic changes were revealed only at the stage of the avoidance recall. The [H-3]-5-HT specific binding was decreased, MAO activity was increased and accompanied by enhanced 5-HIAA transport from serotonergic terminals. No changes were revealed in 5-HT content. It is suggested that the retrieval processes in passive avoidance learning are mediated by serotonergic system of the amygdala.