Fig. 1: Expectation of pain relief activates the rACC→Pn pathway.
a, PAC assay and representative traces of mouse locomotion. Pre, pre-conditioning test; Post, post-conditioning test. b, The time spent in chamber 2 (F1,85 = 48.84, P = 3 × 10−8). c, The latency of the first crossing back (F1,85 = 38.45, P = 5 × 10−7). d, The latency preceding first paw licking (left; P = 0.001), rearing (middle; P = 0.028) and jumping (right; P = 0.013) after reaching chamber 2 during the post-test. e, Nocifensive behaviours after the first border crossing during the post-test. The grey highlighted region indicates the estimated duration (~45 s) of PAC-induced pain relief. f, The frequency of licking (left; P = 0.04) and rearing (middle; P = 0.06) and the duration of rearing (right; P = 0.007) during the first 45 s after the first border crossing on the post-test day in e. g, The strategy to label rACC neurons that are active during PAC. Scale bar, 2 mm. h, Image of rACC neuron cell bodies. i, The density of TRAPed ACC neurons (P = 2 × 10−5). n = 12 per group. Scale bars, 100 μm. j, Axon terminals of TRAPed rACC neurons. CPu, caudate putamen; MD, mediodorsal thalamic nucleus; Th, thalamus; VPM, ventral posteromedial thalamic nucleus; ZI, zona incerta. Scale bars, 100 μm. k, The axon terminal density in each area (F1,63 = 131.691, P = 2 × 10−16). n = 9 and 6 (CPu); 7 and 6 (ZI); 5 and 8 (MD); and 6 and 7 (VPM and Pn) in the control and conditioned groups, respectively. Statistical analysis was performed using two-way analysis of variance (ANOVA) with Tukey post hoc test (b, c and k), two-sided Wilcoxon rank-sum tests (d, f and i). For a–f, n = 9 (control) and 10 (conditioned). For the box plots, the centre lines show the median values, the box limits show the quartiles, and the whiskers show the most extreme datapoints ≤interquartile range from the box edges. For b and c, data are mean ± s.e.m. *P < 0.05, **P < 0.01 and ***P < 0.001.
