Figure 3

IL-6 treatment significantly increased the dural afferent excitability, which was blocked by pretreatment with U0216. (A) Current threshold was measured in dural afferents treated with vehicle (white bar, n = 30), 50 ng/ml IL-6 (black bar, n = 32) or 50 ng/ml IL-6 + 10 μM U0126 (gray bar, n = 13). Significant (**p < 0.01) differences among means for each group were determined by analysis of variance followed by Newman-Keuls post hoc test. Current threshold was significantly lowered after IL-6 treatment (**p < 0.01). Pretreatment with U0126 for 10 mins significantly reversed the hyperexcitability induced by IL-6 (^## p < 0.01). (B) Action potentials were elicited by 25 ms step current injection from resting membrane potential. Horizontal line and arrow indicate 0 and -70 mV membrane potential, respectively. Current threshold for action potentials in the representative dural afferents treated with vehicle, 50 ng/ml IL-6 or 50 ng/ml IL-6 + 10 μM U0126.