Striatal lesions and transplants demonstrate that cholecystokinin receptors are localized on intrinsic striatal neurones: a quantitative autoradiographic study.

Considerable evidence supports the existence of modulatory interactions between cholecystokinin and dopamine in the striatum. In order to explore further the nature of such interactions, the anatomical localization of CCK receptors in rat striatum was investigated autoradiographically following selective lesions. Infusion of 6-hydroxydopamine into the medial forebrain bundle had no effect on striatal CCK receptor content. In contrast, destruction of striatal cell bodies with ibotenic acid or quinolinic acid markedly reduced the number of striatal [125I]CCK-8 binding sites. CCK receptor levels were restored to normal following transplantation of neonatal striatal tissue into rats previously treated with ibotenic acid. These results suggest that CCK receptors are located primarily on intrinsic striatal neurones and not on nigrostriatal afferent fibres.