Figure 2: BK channels are required for the development of morphine-induced hyperalgesia.

(a,c) The time course of the PWT following the i.t. injection of morphine (10 μM)-stimulated primary microglia, whose BK channels were pharmacologically (a) or genetically (c) silenced. Cont mic, non-stimulated primary microglia; Mor-stim mic, morphine-stimulated primary microglia; Mor+Pax-stim mic, morphine+paxilline (2 μM)-stimulated primary microglia (n=6 each). (b,d) Effects of i.t. injection of morphine-stimulated primary microglia on the development of morphine-induced hyperalgesia (n=6 each). The open arrow indicates the i.t. injection of primary microglia. The data represent the means±s.e.m. **P=0.0038, **P=0.0002 (Saline versus Mor-stim Mic), ^†††P=0.0003, 0.0001 (Mor-stim Mic versus Mor+Pax-stim Mic), (drug × time point interaction): F_{3, 60}=20.77, a two-way ANOVA followed by the Bonferroni post hoc test (a). **P=0.0071, ***P=0.0001 (Saline versus Mor-stim Mic), ^††P=0.0014, ^†††P=0.0001 (Mor-stim Mic versus Mor+Pax-stim Mic), (drug × time point interaction): F_{3, 60}=20.77, a two-way ANOVA followed by the Bonferroni post hoc test (b). ***P=0.0001, 0.0001 (Slo1^+/+ Cont Mic versus Slo1^+/+ Mor-stim Mic), ^††P=0.0012, ^†††P=0.0001 (Slo1^+/+ Mor-stim Mic versus Slo1^−/− Mor-stim Mic), (drug × time point interaction): F_{4, 75}=10.6, a two-way ANOVA followed by the Bonferroni post hoc test (c). **P=0.0023, 0.0079, ***P=0.0001 (Slo1^+/+ Cont Mic versus Slo1^+/+ Mor-stim Mic), ^††P=0.0024, ^†††P=0.0001, 0.0001 (Slo1^+/+ Mor-stim Mic versus Slo1^−/− Mor-stim Mic), (drug × time point interaction): F_{4, 175}=27.16, a two-way ANOVA followed by the Bonferroni post hoc test (d).