a, Left, schematic of experimental design to evaluate intracortical drug spread with Alexa633 hydrazide (0.15 μl, 1 μM). Confocal images of serial brain slices (middle) and quantification (right) showing Alexa633 fluorescence mainly restricted in L2/3 of S1 (n = 3 mice). L, lateral; ML, midline; D, dorsal; V, ventral. a.u., arbitrary units. b–d, Left, schematic of experimental design. Mice received daily intracortical injections of AChR antagonist (0.15 μl), at either ZT2 or ZT14, from days 1 to 5 after SNI. Control mice received vehicle (ACSF) injections. Right, nociceptive thresholds in mice. Vehicle controls (dashed line) were shared between (b–d) and Fig. 4d. b, Administration of methyllycaconitine (MLA, 10 nM), an antagonist of α7-containing nAChRs, at ZT2 has minor effects on alleviating SNI-induced mechanical allodynia in mice (n = 6 mice in ZT2 group tested for punctate pain; n = 5 mice per group for other tests; SNI-ZT2 vs. SNI, punctate, F(9, 90) = 2.50, P = 0.013; dynamic, F(3, 27) = 8.83, P = 0.0002; cold, F(3, 27) = 0.65, P = 0.59; hot, F(3, 27) = 0.49, P = 0.69). c, Administration of scopolamine (20 μM), a pan-mAChR antagonist, has no effects on alleviating SNI-induced allodynia in mice (n = 6 mice per group; SNI-ZT2 vs. SNI, punctate, F(9, 90) = 1.49, P = 0.16; dynamic, F(3, 30) = 0.50, P = 0.69; cold, F(3, 30) = 0.07, P = 0.97; hot, F(3, 30) = 0.78, P = 0.51). d, Administration of AF-DX 116 (150 nM) and PD102807 (200 nM), M2- and M4-containing mAChR antagonists, has no effects on alleviating SNI-induced allodynia in mice (n = 5 mice per group; SNI-ZT2 vs. SNI, punctate, F(9, 81) = 1.99, P = 0.051; dynamic, F(3, 27) = 1.07, P = 0.38; cold, F(3, 27) = 0.95, P = 0.43; hot, F(3, 27) = 1.63, P = 0.21). Mean ± SEM. *P < 0.05, ** P < 0.01, *** P < 0.001; NS, not significant; by two-way ANOVA followed by Bonferroni’s test (two-sided). Detailed statistics in Supplementary Table 1.