Spontaneous recovery from motor asymmetry in adult rats with 6-hydroxydopamine-induced partial lesions of the substantia nigra.

Animals with 6-hydroxydopamine-induced partial unilateral lesions of the substantia nigra exhibit spontaneous recovery from motor asymmetry, a transitory increase in dopamine turnover and an increase in tyrosine hydroxylase activity in the denervated striatum. The recovery of function in these animals seems to be due to the compensatory increase in dopamine metabolism as well as due to the time-dependent increase in tyrosine hydroxylase resulting from either enzyme activation or following reinnervation of the denervated striatum by nigral efferents spared by the partial lesions.