NGF decreases the level of apoptosis in spinal cord lesions. A. TUNEL apoptosis assay of model rat spinal cord lesions. Immunofluorescence result of the TUNEL assay. Bright green dots were deemed positive apoptosis cell, magnification was 20×. B. The analysis of apoptosis cell of the sham, SCI and NGF treatment groups. The percentage of apoptosis was counted from 3 random 1 × 1 mm2 areas. C. Protein expressions of caspase-3 for the sham, SCI and NGF treatment groups. D. The optical density analysis of caspase-3 protein. * P < 0.05 versus the SCI group, and # P < 0.05 versus the sham group. ** P < 0.01 versus the SCI group, and ## P < 0.01 versus the sham group. Data are the mean values ± SEM, n = 6.