D2 DOPAMINE RECEPTOR DISTRIBUTION IN THE RODENT CNS USING ANTIPEPTIDEANTISERA

D2 dopamine receptors were identified immunohistochemically in rodent tissues using anti-peptide antisera to distinguish regional and cellul ar staining patterns. These subtype selective polyclonal antibodies we re directed against both extracellular and intracellular regions of th e native protein and showed that the D2 dopamine receptors are widely distributed within the nervous system. The highest expression of D2-li ke dopamine receptor immunoreactivity was visualized in the forebrain and components of the basal ganglia, supportive of previous investigat ions of the D2 dopamine receptor distribution using in vitro autoradio graphic ligand binding or in situ hybridization for its messenger RNA. The anti-peptide antisera could detect the dopamine receptor in both perfusion-fixed and fresh-frozen tissue preparations. The reactive cel ls and their processes could be distinguished using experimental incub ations from 1:8,000 (in immunofluorescence processing) to 1:80,000 (in immunoperoxidase processing) in the most reactive nervous system regi on, the neostriatum. The antisera are selectively directed against ext racellular or intracellular epitopes in both the long and short isofor ms of the D2 dopamine receptor, and should prove useful in subsequent studies of the subcellular distribution of this receptor in particular , and the dopamine system in general.