N-methyl-D-aspartate receptor antagonist MK-801 induced circling behavior in rats with unilateral striatal ischemic lesions or nigral 6-hydroxydopamine lesions.

The present study shows that systemic administration of the selective, non-competitive N-methyl-D-aspartate antagonist MK-801 [(+)-5-methyl-10,11-dihydroxy-5H-dibenzo (a,d)-cyclohepten-5,10-imine] dose-dependently induces ipsiversive rotational behavior in the rats with a unilateral striatal lesion produced by transient middle cerebral artery occlusion or in those with a unilateral nigrostriatal lesion produced by 6-hydroxydopamaine. In relation to a functional model of the basal ganglia-thalamocortical 'motor' circuit, the present data suggest that the striatum may be one of the most important sites where MK-801 acts in the basal ganglia, with its being responsible for the circling behavior of the animal models.