Identification of dopamine D1-alpha receptor within rodent nucleus accumbens by an innovative RNA in situ detection technology

In the central nervous system, the D1-alpha subtype receptor (Drd1α) is the most abundant dopamine (DA) receptor, which plays a vital role in regulating neuronal growth and development. However, the mechanisms underlying Drd1α receptor abnormalities mediating behavioral responses and modulating working memory function are still unclear. Using a novel RNA in situ hybridization assay, the current study identified dopamine Drd1α receptor and tyrosine hydroxylase (TH) RNA expression from DA-related circuitry in the nucleus accumbens (NAc) area and substantia nigra region (SNR), respectively. Drd1α expression in the NAc shows a "discrete dot" staining pattern. Clear sex differences in Drd1α expression were observed. In contrast, TH shows a "clustered" staining pattern. Regarding TH expression, female rats displayed a higher signal expression per cell relative to male animals. The methods presented here provide a novel in situ hybridization technique for investigating changes in dopamine system dysfunction during the progression of central nervous system diseases.