Inhibition of the electrically induced release of [3H]dopamine by serotonin from superfused rat striatal slices.

The effect of serotonin (5-hydroxytryptamine) on the electrically induced release of [3H]dopamine from superfused slices of the rat striatum has been studied. It was observed that serotonin produced a concentration dependent decrease in the field stimulation-induced release of [3H]dopamine with the threshold concentration being 10(-6) M or lower. Methysergide, in a concentration which did not alter the evoked release, antagonized the inhibitory effect of serotonin. The present results suggest that serotonin should be added to the list of endogenous substances that can influence dopaminergic transmission in the striatum.