ER stress-induced apoptosis was involved in the early stage of SCI. A. Immunohistochemistry for GRP78, CHOP and caspase-12 in sham, 1, 3, 7 and 14 d after spinal cord injury lesions groups. B. Analysis of the positive cells of the immunohistochemistry results. * represents P < 0.05 versus the sham group, ** P < 0.01 versus the sham group, # P < 0.05 versus the 1d group, and $ P < 0.05 versus the 3 d group, & P < 0.05 versus the 7 d group. Data are the mean values ± SEM, n = 6.