Discrete quinolinic acid lesions of the lateral but not of the medial caudate-putamen reversed haloperidol-induced catalepsy in rats.

Discrete lesions in the medial or lateral subregion of the rostral caudate-putamen (CP) were induced by bilateral intracerebral injections of a low dose of quinolinic acid (30 nmol in 1 microliter/per side) in rats. Quinolinic acid lesions in the lateral CP potently reversed haloperidol-induced catalepsy (0.5 mg/kg,i.p.), while lesions in the medial CP were not effective. Spontaneous locomotor activity was not altered significantly after quinolinic acid lesions of either the medial or lateral CP. These results show that the lateral CP seems to be important for the expression of neuroleptic-induced catalepsy and thus further corroborate the concept of a functional heterogeneity of the striatum.