Fig. 8

IFN-I activation reduces neuraxial opioid-induced acute itch and spinal phosphorylation of ERK in mice. A Experimental design for recombinant IFN-α and IFN-β treatment in intrathecal (i.t.) opioid-induced itch. B pre-administration of recombinant IFN-α and IFN-β attenuates i.t. morphine-induced scratching behaviors. n = 8 mice/group. C Morphine antinociception, assessed by Tail-flick test, is not impaired by recombinant IFN-α and IFN-β therapy. n = 8 mice/group. D Locomotor function, assessed by Rotarod test, is unaffected by recombinant IFN-α and IFN-β therapy. n = 6 mice/group. E and F Western blot showed that recombinant IFN-α treatment inhibits spinal phosphorylation of ERK at 30 min after morphine injection. n = 6 mice/group. Data are expressed as mean ± SD and analyzed by one-way ANOVA with Bonferroni post hoc test (B and F), and two-way ANOVA with Bonferroni post hoc test (C and D). Compared with group Saline, ^****P < 0.0001. n.s., not significant