Head withdrawal threshold and food intake in normal rats was not affected by retigabine and XE991. (A), RTG (retigabine) at 7.5 mg/kg and XE991 at 3 mg/kg had no effect on head withdrawal threshold of normal rats without TMJ inflammation, as compared with the vehicle (two-way ANOVA followed by Bonferroni post-test). (B), Food intake values in normal rats without TMJ inflammation. During the 2 h period of food intake, retigabine (RTG) and XE991 had no effect on normal food intake in rats without TMJ inflammation. The food intake value in the baseline group (4.8 g) indicates the normal value obtained before drug or vehicle administration. The food intake values in the groups treated by retigabine (7.5 mg/kg, i.p.) and XE991 (3 mg/kg, i.p.) were 4.5 g and 4.8 g, respectively. The food intake value of the vehicle group was 5.5 g. There was no statistical significance between these four groups (one-way ANOVA followed by Dunnett's test).