CELLULAR-DISTRIBUTION OF THE RAT D-4 DOPAMINE-RECEPTOR PROTEIN IN THECNS USING ANTIRECEPTOR ANTISERA

A polyclonal antiserum was generated against a unique peptide fragment in the rat D-4 dopamine (DA) receptor. The titer was monitored using solid-phase ELISA and once it was established, specificity was assesse d using Chinese Hamster Ovary (CHO) cells, stably transfected with the full-length cDNA for the rat D-4 DA receptor. Immunofluorescent stain ing produced by incubation with the anti-D-4 DA receptor antiserum was selective for D-4 DA receptor-transfected CHO cells, and was expresse d at their cell membranes and cytoplasm. Attenuated staining for D-4 D A receptor protein was visible in untransfected, K1 CHO cells, and in D-2 or D-3 DA receptor-transfected CHO cells. The regional and cellula r CNS distribution patterns for the D-4, DA receptor subtype were exam ined, and illustrated significant protein levels within the frontal (F Cx) and parietal cortices. Lesser amounts of receptor protein staining occurred in the thalamus, globus pallidus, hippocampus, cerebellar ve rmis, and very low expression was detected in the striatum (CPu). D-4 DA receptor protein staining was correlated with the cellular expressi on of its mRNA transcripts in these same brain regions using concurren t fluorescent analyses. The homologous coincidence in staining pattern s for the D-4 DA receptor transcripts and encoded proteins in identifi ed neurons of the FCx and CPu showed variations in receptor expression in these identified basal ganglia pathways. (C) 1997 Elsevier Science B.V.