D-1 dopamine receptor changes after striatal quinolinic acid lesion.

Regional changes in the distribution of D-1 dopamine receptors produced by unilateral striatal lesions were evaluated in rat brain by quantitative autoradiography. Lesions were induced by local infusion of quinolinic acid, an endogenous excitotoxin that destroys intrinsic neurons, but spares fibers of passage. D-1 receptor density, as determined by [125I]SCH 23982 binding, was reduced in caudate-putamen, globus pallidus, substantia nigra, nucleus entopeduncularis on the lesioned side. These results confirm the presence of D-1 receptors on striatal cell bodies and provide direct evidence for the existence of presynaptic D-1 receptors on the terminals of striatal projections.