Relative gene expression levels of glial activation (A and B), inflammatory cytokines (C-E) and activating transcription factor 3 (ATF3) (F) in the spinal cord at 2 days after chronic constriction injury (CCI) of the sciatic nerve. Sham, mice that were subjected to sham operation without sciatic nerve ligations. Air, mice that breathed air alone after CCI. H2S, mice that breathed hydrogen sulfide at 40 ppm for 8 h on 2 consecutive days after CCI. ITGAM, integrin alpha M; GFAP, glial fibrillary acidic protein; IL-6, interleukin 6; CCL2, chemokine CC motif ligand 2; TNF-α, tumor necrosis factor α. N = 8 in each group. *P < 0.05, **P < 0.01, and ***P < 0.001. Data were analyzed using one-way ANOVA with a Bonferroni post hoc test.