A higher density of the D1 and the D1/D2 MSNs in the Acb is congruent with an overall higher density of all MSNs in the shell (298.6 ± 15.0) and the core (267.9 ± 24.5 cells/mm3) compartments of the Acb compared to the dorsal striatum (123.5 ± 5.4 × 103 cells/mm3).