Figure 7.

Antidepressants differentially attenuated the second phase of formalin-induced nociceptive behavior in wild-type mice and Lmx1b^f/f/p mice. A, B, Both fluoxetine (20 mg/kg, i.p.) and duloxetine (30 mg/kg, i.p.) injection significantly inhibited the second phase of pain behavior compared with the vehicle injection in wild-type mice (n = 8–12). C, D, Fluoxetine (20 mg/kg, i.p.) has no significant inhibitory effect on the second phase of formalin pain behavior, but duloxetine (30 mg/kg, i.p.) still has the effect compared with the vehicle injection in Lmx1b^f/f/p mice (n = 8–12). *p < 0.05, two-way ANOVA followed by Fisher's post hoc test. WT, Wild type.