and the mechanisms of Parkinson’s disease.3,4 However, the striatum and BG are involved in many behaviors besides the control of movement. For example, segregated neurochemical compartments in the dorsal striatum (DS) known as striosome (patch) and matrix are thought to participate in limbic and sensorimotor functions, respectively.5-7 Similarly, the ventral striatum (VS) has fundamental roles in reward processing, learning, and emotional responses.8-11 The traditional model, that involves competition between signals in the direct and indirect pathways, does not account for these broad functional roles. Rather, these broad functionalities indicate deeper cell-type and circuit heterogeneity.
