Regional analysis of the effects of NTS2 agonist administration on formalin-induced c- fos expression in spinal cord. Data represent the mean ± SEM of c-fos-positive neurons in the superficial laminae (laminae I-II), nucleus proprius (laminae III-IV), neck of the dorsal horn (laminae V-VI), and lamina X of the L4-L5 segments, both ipsilateral (a) and contralateral (b) to formalin injection. Formalin increased c-fos expression in rats pretreated with saline compared to that for naïve rats. JMV-431 (30 μg/kg) and levocabastine (5 μg/kg) reduced the number of c-fos positive neurons in laminae I-II, III-IV and V-VI on the ipsilateral side. Both NTS2 agonists also reversed the spinal neuronal activity observed contralaterally. Statistical analysis between saline and agonist-treated groups: * P < 0.05 and ** P < 0.01; ANOVA followed by Dunnett's multiple comparison test.