Figure 2.

The TAN pause duration positively correlates with the reward prediction error (RPE). Thalamic stimulus induces an initial burst of TAN activity, followed by a TAN pause. The blue curve is TAN activity; the orange curve is dopamine (DA) concentration; the purple curve is the slow after-hyperpolarization current I_sAHP and the green curve is the h-current I_h. (A) RPE = 1, the dopamine concentration increases during the TAN pause as a result of the positive RPE, which slows down I_h activation and thus prolong the pause. (B) For RPE = 0, the TAN pause is shorter, because there is no phasic change in dopamine release, so the concentration of dopamine remains at baseline during the TAN pause. (C) RPE = −1, the TAN pause is even shorter than for RPE = 0 because there is a net decrease in dopamine concentration during the pause, which provides the fastest I_h activation and hence, the shortest pause in TAN activity. Thalamic stimulation duration was 300 ms. TP stands for TAN pause duration in milliseconds.