The influence of antiserotonergic agents on the action of dopaminergic drugs

The effect of drugs blocking serotonin receptors: cyproheptadine, methysergide, and methergoline, and of serotonin synthesis inhibitor, p-chlorophenylalanine on the stereotyped behavior and number of rearings of the rats receiving apomorphine, amphetamine, nomifensine and 1,3-dimethyl-5-aminoadamantane was investigated. The blockade of serotonin receptors potentiates behavioral effects of dopamine agonists. It is concluded that central serotonin may play an inhibitory role, antagonistic to that of catecholamines.