Quantitative autoradiographic localization of D-1 dopamine receptors in the rat brain: use of the iodinated ligand [125I]SCH 23982.

In vitro autoradiography was used to visualize [125I]SCH 23982 binding sites in rat brain. Labeling was concentrated in the caudate-putamen, accumbens nucleus, olfactory tubercle, substantia nigra pars reticulata and the entopeduncular nucleus. [125I]SCH 23982 labels predominantly D-1 receptors but also labels 5-HT2 receptors in certain areas of the brain. These findings may relate to the distribution of dopamine's cerebral loci of action on D-1 receptors.