title: Circling behavior in rats with partial, unilateral nigro-striatal lesions: effect of amphetamine, apomorphine, and DOPA.
abstract: Partial, unilateral lesions of the nigro-striatal tract were produced in rats by injecting various quantities of 6-hydroxydopamine into the substantia nigra. The extent of each animal's lesion was estimated by comparing tyrosine hydroxylase activities in its lesioned and control striata. L-DOPA and apomorphine induced contralateral (i.e., away from the lesion) circling behavior only in rats in which more than 90% of the nigro-striatal system had been destroyed. In contrast, d-amphetamine caused turning in the ipsilateral direction when as few as 50% of the nigro-striatal neurons had been destroyed.
mesh_terms: D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001519:Behavior / Q000187:drug effects*; D003342:Corpus Striatum / Q000502:physiology*; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects*; D013378:Substantia Nigra / Q000502:physiology*
chemical_list: D006892:Hydroxydopamines; D007980:Levodopa; D000661:Amphetamine; D001058:Apomorphine