Lennart Heimer's original drawing, illustrating his concept that the ventral striatopallidum is integral with the basal ganglia's striato-pallidopthalamic loop. Reproduced with permission from Heimer et al. (1982). VS, Ventral striatum; VP, ventral pallidum; MD, medio-dorsal thalamus; VA, ventralis anterior complex of the thalamus; VL, ventralis lateralis complex of the thalamus; GP, globus pallidus; C-P, caudate putamen. While not indicated in this illustration, Heimer included the nucleus accumbens as part of the VS.