Figure 1

Time course of the effects of β-FNA on the antinociceptive actions of AM1241 and EA on thermal hyperalgesia and mechanical allodynia in rats. A, Effects of β-FNA on the AM1241 action on thermal withdrawal latency in response to heat stimulus applied to the inflamed paw. B, Effects of β-FNA on the analgesic effect of EA on thermal withdrawal latency in response to heat stimulus applied to the inflamed paw. C, Effects of β-FNA on analgesic action of AM1241 on mechanical withdrawal threshold in response to von Frey filaments applied to the inflamed paw. D, Effects of β-FNA on the analgesic action of EA on mechanical withdrawal threshold in response to von Frey filaments applied to the inflamed paw. Time 0 represents baseline values before CFA injection. EA (2 Hz) or sham EA was administered every other day for 30 min, and AM1241 or its vehicle (50 μL) was injected subcutaneously into the dorsal surface of the left hindpaw of rats at the same time of EA, as indicated by white arrows. β-FNA or its vehicle was injected 24 hours before AM1241, EA or sham EA treatment as indicated by black arrows. Data are presented as means ± SEM (n = 8 rats in each group). *P < 0.05, compared with the vehicle control group; #P < 0.05, compared with the CFA+vehicle of AM1241 group; &P < 0.05, compared with the CFA+AM1241 group; †P < 0.05, compared with the CFA+sham EA+vehicle of β-FNA group; $P < 0.05, compared with the CFA+EA+vehicle of β-FNA group (Two-way ANOVA followed by Bonferroni's test).