Extended Data Fig. 2: Effects of morphine treatment on pain threshold and on the proportion of splenic T_H2 immune cells in SNI mice.

a, Schematic for the morphine treatment of SNI 1D mice. b,c, Effects on pain threshold (b) and the proportion of CD4⁺ IL-4⁺ and CD4⁺ IL-10⁺ cells in spleens (c) of SNI 1D mice after morphine treatment. d, Schematic for morphine treatment of SNI 4W mice. e,f, Effects on pain threshold (e) and the proportion of CD4⁺ IL-4⁺ and CD4⁺ IL-10⁺ cells in spleens (f) of SNI 4W mice after morphine treatment. Significance was assessed by two-way repeated-measures ANOVA with post hoc comparison between groups in (b,e), and two-tailed unpaired Student’s t-test in (c,f). All data are presented as the mean ± SEM. *P < 0.05, ***P < 0.001. Details of the statistical analyses are presented in Supplementary Table 1.