Western blot quantification of JNK and pJNK expressions after different treatments. A: Compared with that of Sham-Saline group, no difference could be detected in pJNK expression after intrathecal ketamine (300 μg kg-1) to sham-operated rats, whereas SNL apparently induced pJNK up-regulation. However, intrathecal ketamine down-regulated SNL-induced pJNK expression in a dose-dependent manner, which was in accord with the immunofluorescent histochemical staining result. B: Spinal JNK protein expression did not show any obvious difference after different treatments. *, # or $ each indicates statistically significant difference with P < 0.05 between groups. There were six rats in each group. KTM: ketamine.