The role of the dorsal striatum in reward and decision-making

Abstract

Although the involvement in the striatum in the refinement and control of motor movement has long been recognized, recent description of discrete frontal corticobasal ganglia networks in a range of species has focused attention on the role particularly of the dorsal striatum in executive functions. Current evidence suggests that the dorsal striatum contributes directly to decision-making, especially to action selection and initiation, through the integration of sensorimotor, cognitive, and motivational/emotional information within specific corticostriatal circuits involving discrete regions of striatum. We review key evidence from recent studies in rodent, nonhuman primate, and human subjects.

Figure 1.

Corticostriatal circuits involved in decision-making. a, b, The learning processes controlling the acquisition of reward-related actions are mediated by converging projections from regions of anteromedial prefrontal cortex (MPC) to the rodent dorsomedial striatum or primate dorsoanterior striatum (DM), whereas the processes mediating the acquisition of stimulus-bound actions, or habits, are thought to be mediated by projections from sensorimotor cortex (SM) to the rodent dorsolateral–primate dorsoposterior striatum (DL) (b). These corticostriatal connections are parts of distinct feedback loops that project back to their cortical origins via substantia nigra pars reticulata (SNr)/globus pallidus internal segment (GPi) and the mediodorsal (MD)/posterior (PO) nuclei of the thalamus. c, Reward and predictors of reward are the major motivational influences on the performance of goal-directed and habitual actions that are thought to be mediated by corticostriatal circuits involving, particularly, ventral striatum (VS) and regions of the amygdala. Dopamine is an important modulator of plasticity in the dorsal striatum, whereas its tonic release has long been associated with the motivational processes mediated by the ventral circuit. VTA, Ventral tegmental area; SNc, substantia nigra pars compacta.