On Day 57, all rats were anesthetized (100 mg/kg sodium pentobarbital, I.P.). Thereafter intracardially perfused with 0.9% saline followed by 10% buffered formalin. A spinal cord segment at the level of T12-L1 was dissected, postfixed in 10% buffered formalin overnight, cryoprotected in 30% sucrose for 48 hr and serially transverse sectioned using a cryostat (B1155800 Sakura) at 10 µm thickness. All sections were processed for hematoxylin and eosin staining and assessed under light microscopy (Byrnes et al., 2010). Standard immunohistochemistry for the glial scar (glial fibrillary acidic protein) and myelination (myelin basic protein [MBP]) was performed for all of the sections. For immunohistochemistry, sections from formalin-fixed, paraffin-embedded spinal cord tissues were dewaxed, rehydrated, and retrieval of antigens was performed. After incubation with 3% H2O2 in methanol, and then normal nonimmune goat serum, the sections were incubated with rabbit antiactive glial fibrillary acidic protein (GFAP) polyclonal antibody and mouse monoclonal MBP primary antibody (Santa Cruz Biotechnology), at a dilution of 1:200 at 4℃ for overnight, followed by biotinylated goat anti-rabbit IgG for 20 min at room temperature, and subsequently incubated with streptavidin–peroxidase (All from Santa Cruz Biotechnology). PBS replaced primary antibody as the negative control. 3,3′-Diaminobenzidine chromogen was applied for visualization of peroxidase activity. Finally, the sections were counterstained with hematoxylin (Fleming et al., 2006; Hosseini et al., 2015).