Fig. 5

Spinal inhibition of P2X7 receptors during the early phase of CIA attenuated mechanical hypersensitivity, spinal microgliosis and increases in the levels of the pro-inflammatory cytokine IL1-β in CSF. Intrathecal (i.t.) administration of the P2X7 antagonist (A-438079, 50 μg/day) from 1 day before immunization until day 7 post-immunization significantly prevented mechanical hypersensitivity in CIA rats (a), reduced spinal microgliosis (b) and the increased levels of IL-1β in CIA rats (c). Values are mean ± SEM of 8 rats per group. ***p < 0.001, **p < 0.01, *p < 0.05 compared to vehicle group; #p < 0.05 compared to control group (a two-way RM ANOVA, post hoc Tukey’s test; b t test; c one-way ANOVA, post hoc Tukey’s test)