Intensification of amphetamine-induced excitation by methysergide, a serotonergic receptor blocker

Methysergide, a serotonergic receptor blocker, was studied to determine its effects against d-amphetamine-induced excitation as measured by convulsions elicited by handling in mice. Significant intensification (p less than 0.01) of the action of d-amphetamine was observed in mice. These results indicate that reduction in serotonergic activity in the central nervous system enhances excitation induced by d-amphetamine.