Abstract: Both the load of large dose of L-DOPA in mice and injection of 6-hydroxy-dopamine into cerebral ventricles in rabbits 3 days before caused a prolonged anaesthetic period induced by scopolamine injected cerebroventrically(P<0.05).It was suggested that the dopaminergic system in the brain exerts certain influences on the function of the cholinergic system. Scopolamine, however not show any effect on the cAMP level and D_1 receptor in rat brain.