a, b Representative images and quantification of the number of Nissl positive cells in the posterior horn area of the spinal cord in each group at 14 d after SCI (n = 5). Scale bar = 50 μm. c, d Immunofluorescence staining of Cleaved caspase-3 (green) and NeuN (red), and the quantification of the number of NeuN-positive cells in the posterior horn area of the spinal cord in each group at day 14 after SCI (n = 5). Scale bar = 50 μm. e, f Western blotting result and quantification of Cleaved caspase-3 in each group at day 14 after SCI (n = 3). #P < 0.05 vs. Sham group, *P < 0.05, **P < 0.01 vs. SCI group. SCI spinal cord injury, Met metformin.