The neurological basis of motor asymmetry following unilateral 6-hydroxydopamine brain lesions in the rat: the effect of motor decortication

The role of the motor cortex in the mediation of asymmetric movement after unilateral 6-hydroxydopamine (6-OHDA) brain lesions has been examined in the rat. The effect of unilateral and bilateral sensorimotor decortication upon spontaneous and drug (apomorphine and amphetamine)-induced motor asymmetry has been studied following unilateral injection of 6-OHDA into the lateral hypothalamus. Both bilateral decortication and unilateral decortication on the side of the 6-OHDA lesion caused a transient reversal of the spontaneous motor asymmetry normally seen in 6-OHDA lesioned animals. Neither unilateral nor bilateral sensorimotor decortication abolished drug-induced turning behaviour. It is postulated that subcortical basal ganglia efferent pathways may be involved in the mediation of motor asymmetry after unilateral 6-OHDA lesions of the nigrostriatal dopaminergic projection.