FIG. 3.

Representative immunohistochemistry (IHC) SMI-31 (phosphorylated neurofilament, intact axons, green) and triple staining with SMI-312 (anti-total neurofilament, total axons, green), MBP (myelin basic protein, myelin sheaths, red), and DAPI (4′,6-dianidino-2-phenylindole, cell nuclei, blue) from one control and two spinal cord injury (SCI) with different injury severities (based on tissue damage). Compared with a control mouse (A, D), white matter swelling was obviously seen in SCI mice under 10 × images (B, C, E, F). Reduced SMI-31 signal intensity in SCI mice (B, C) suggests axonal injury. Three representative 20 × zoom-in triple IHC stained images of right (a, b, c), middle (d, e, f), and left (g, h, i) ventral white matter column from each spinal cord is presented. The control mouse (a, d, g) demonstrated dense yellow staining reflecting high density and strong signal intensity from SMI-312 (green) and MBP (red) with light DAPI (blue). The larger green spots (white arrows), reduced yellow-staining signal (combined with green and red), and increased voids in both moderate and severe spinal cords suggest co-existing axonal swelling, injury, demyelination and axonal loss (b, c, e, f, h, i). Increased DAPI staining (blue) is also seen in both SCI mice, associated with cell infiltration (b, c, e, f, h, i). Yellow scale bar in 10 × : 200 μm. White scale bar in 20 × : 100 μm.