(A) Schematic drawing of the experimental design for recording DA neuron activity in the monkey with unilateral V1 lesion. (B) Averaged spike waveforms of a presumed DA neuron in SNc and a non-DA neuron in the SNr. Amplitude of these spikes are normalized. Spike width was defined as the time between the first negative peak and second positive peak. (C) Histogram of the spike width. Red bars indicate the DA neurons and blue bars indicates the SNr neurons. (D) Left; a low magnification view of the SNc and surrounding structures stained with anti-TH immunohistochemistry. Scale bar = 5.0 mm. Right; a high magnification view of the area indicated by a blue square. Red arrows indicate locations of electrolytic markings. Scale bar = 2.0 mm. (E) Time course of the Pavlovian conditioning task (the same as Figure 1B). (F) A typical DA neuron activity in V1 lesioned monkeys. Raster plots of a DA neuron from LR (red) and SR (blue) trials were sorted and shown on the top, receptively. The first trial was plotted at the bottom of the raster plot and the last trial was plotted at the top. Red and blue lines indicate average firing rates during LR and SR trials, respectively. These plots were aligned at the FP onset, CS onset, and RW delivery (left, middle and right panels, respectively). (G) Responses of all recorded DA neurons to FP, CS and RW (left, middle and right panels) are superimposed. A thick red line in each panel is the averaged firing rate of DA neurons in LR trials, and a thick blue line is the averaged firing rate in SR trials. Thin lines behind the averaged lines are the averaged responses of individual neurons in LR trials (red) and in SR trials (blue), respectively. (H) Firing rates of individual DA neurons within the time windows (100–300 ms from FP and CS or 150–350 ms from RW; left, middle and right panels). Blue lines indicate the average of all the neurons and SD of the firing rate in LR trials and in SR trials. * = significant difference (N = 24, p=0.82 (FP), p=1.1 × 10−7 (CS), p=0.27 (RW), Wilcoxon signed-ranks test, α <0.05). (I) The yellow background in the figures shows the period during which the responses to LR-CS and SR-CS were significantly different more than 15 ms (N = 24 in affected, N = 16 in intact, two-sided sign test, α <0.05). The two panels show averaged DA responses to CSs presented to the lesion-affected visual field (upper panel), and to the visual field (lower panel). Arrows under each figure indicate the earliest points where the LR and SR responses can be reliably discriminated for more than 50 ms (122 ms in the lesion-affected visual field, and 112 ms in intact visual field).