Basal ganglia and cerebral cortical distribution of dopamine D1- and D2-receptors in neonatal and adult cat brain.

Quantitative receptor autoradiography was performed on neonatal and adult cat brains. Serial sections through the basal ganglia were assayed for D1- and D2-dopamine receptors and acetylcholinesterase (AChE) staining. The neonatal basal ganglia revealed patches of increased D1-receptor density that frequently overlapped with patches of increased AChE staining, while the D2-receptor distribution was more homogeneous. The adult basal ganglia revealed a mild amount of heterogeneity for both the D1- and D2-receptors, varying from 10 to 25%, with little correspondence to the marked heterogeneity seen with AChE staining. A distinct laminar distribution of the D1-receptor, without significant D2 binding, was seen in the cerebral cortex.