has soma location has soma location expresses expresses striatum neuron medium spiny neuron D1/D2-hybrid medium spiny neuron 2023-06-02T15:19:45Z It has been noted in non-human primate species that the D1/D2-hybrid medium spiny neuron (D1/2) cell type shows the same amount of DRD1 expression as nearby D1 medium spiny neurons but far less DRD2 expression compared to nearby D2 medium spiny neurons. In Rhesus macaques, RXFP1 has been noted as a highly specific marker gene for the D1/2 cell type. The D1/2 cell type has also been described as having characteristics similar to a novel medium spiny neuron described in rodents (D1H or eccentric spiny projection neuron). Although an extrastriosomal cell type, the D1/2 cell type had been noted to express many of the genes associated with striosome, suggesting a possible homology to ‘‘exo-patch’’ cells. D1/D2-hybrid MSN D1/D2 hybrid hybrid D1/2 cell type D1/2 A medium spiny neuron that expresses both DRD1 and DRD2 and is part of an extra-striosomal part of dorsal striatum. Homo sapiens D(1A) dopamine receptor D(2) dopamine receptor dorsal striatum