The effects of the JNK inhibitor, SP 600125, on formalin-induced nocifensive behaviors. For these experiments groups of mice (n = 8) first underwent intrathecal injection of SP 600125 or vehicle 3 h prior to formalin injection. The total duration of licking/biting time during early (0-5 min) and late phase (10 k-60 min) of the formalin response were measured and averaged for either the entire phase (graph A) or in 5-min intervals (graph B). Bars and symbols represent mean ± S.E.M. *p < 0.05, ***p < 0.001 compared to the vehicle group.