part_of part of part of has soma location has soma location striatum neuron indirect pathway medium spiny neuron striosomal D2 medium spiny neuron striosome D2 medium spiny neuron A DRD2-expressing medium spiny neuron that is part of a striosome of dorsal striatum. In Rhesus macaques, both striosomal D1 and D2 medium spiny neuron (MSN) cell types have been noted to have enriched gene expression of the following: KCNT1, KHDRBS3, FAM163A, BACH2, and KCNIP1. Striosomal MSN activations have been noted to influence cognitive and emotional decision making and value-based learning. In contrast to matrix MSNs, striosomal MSNs receive input from limbic territories, including the anterior cingulate cortex, orbitofrontal cortex, and anterior insular cortex, and project directly to midbrain dopamine neurons. dorsal striatum striosome