Striatal cholinergic receptors and dyskinetic motor activity in the rat

An injection of D-tubocurarine into the rat striatum produces a complex motor syndrome resembling in part that induced by picrotoxin. The destruction of the dopaminergic terminals by 6-hydroxydopamine does not prevent these effects of D-tubocurarine on motor activity. Hence neither dopamine release nor the presynaptic acetylcholine receptors are responsible for the D-tubocurarine-induced movements. On the other hand, lesion of the striatum by kainic acid abolishes the motor abnormalities due to D-tubocurarine but not those due to picrotoxin injection. Therefore, the effects of picrotoxin might be attributable to an action on GABA receptors still present in the kainic acid-treated striatum, whereas the effects of D-tubocurarine might be due to its action on striatal postsynaptic acetylcholine receptors.