CGRP prevents electroconvulsive shock-induced amnesia in rats.

The effects of calcitonin gene-related peptide (CGRP) on electroconvulsive shock (ECS)-induced amnesia and the possible involvement of neurotransmitters in this action were studied in rats. ECS-induced amnesia was elicited in a passive avoidance paradigm. The possible roles of different transmitters involved in mediating CGRP action were followed by pretreating the animals with different receptor blockers in doses which themselves could not influence the paradigm. CGRP facilitated learning in the passive avoidance paradigm and prevented ECS-induced amnesia in a dose-dependent manner. Pretreatment with atropine, naloxone, phenoxybenzamine, or propranolol blocked the antiamnesic action of CGRP. Other receptor blockers, such as bicuculline, methysergide, and haloperidol, were ineffective. The results support our previous findings that CGRP facilitates passive avoidance learning and prevents ECS-induced amnesia. In the antiamnesic action of CGRP, cholinergic, opiate, and alpha- and beta-adrenergic mediators are involved.