Effects of NTS2 selective agonists on stereotypic behavior reactions to formalin. The cumulative nociceptive response time of lifting, licking, shaking and biting the injected paw was measured during the second phase (21–60 min). Both NTS2 agonists JMV-431 (a, b) and levocabastine (c, d) significantly reduce phase 2 lifting but do not reverse formalin-evoked licking/shaking/biting behaviors. The vertical bars denote SEM. * P < 0.05 and ** P < 0.01 when compared with the saline-treated group (ANOVA followed by Dunnett's multiple comparison test).