Fig. 6: Activity modulation of nigrostriatal systems by recent rewards.

a The action-related activity (Go cue and movement onset; green lines) exhibited a homogeneous enhancement (higher firing activity or local DA release) with higher reward rate (solid line), i.e., reward expectation, across diverse neuron types and regions. Contrastingly, the outcome-related activity (red lines, rewarded; blue lines, non-rewarded) showed a heterogeneous relationship with reward rate. Small vertical arrows indicate activity increase/decrease with higher reward rate. Large light green and red arrows represent possible effects of reward expectation on action- and outcome-related activities, respectively.