Effect of menthol on expression of TRPM8 protein in ipsilateral L5 DRGs of CCI rats. Immunohistochemical staining (A) and western blot analysis (B) of TRPM8 protein in L5 DRGs from sham-operated rats treated with normal saline or menthol and CCI rats treated with normal saline or menthol. Data are expressed as mean ± SEM. **P < 0.01 vs. Sham-NS rats; §§P < 0.01 vs. Sham-Menthol rats (one-way ANOVA followed by SNK test). Magnification of immunohistochemical images is 400 ×, and scale bars represent 25 μm. Arrows indicate TRPM8 positive neurons.