Parallel Excitatory and Inhibitory Neural Circuit Pathways Underlie Reward-Based Phasic Neural Responses

Figure 9

The phasic activity of DA neurons given different weights of synapses from VP to GPb. Yellow lines indicate the activity of DA neurons when equals 1.00 and equals 0.19431, blue lines indicate the activity when equals 1.10 and equals 0.20307, and red lines indicate the activity when equals 0.90 and equals 0.18608. (a) Trial 1: phasic peak activity responds to unconditional reward. (b) Trial 2: the phasic activity shifts to the cue. (c) Trial 99: the phasic activity upon the cue and baseline activity upon the reward. (d) Trial 100: the dip activity upon reward omission. (e) Trial 199: the dip activity upon nonrewarding cue. (f) Trial 200: the peak activity upon unexpected reward.

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