Figure 5. Histological photographs of spinal cord lesions in Canine 2 (upper row) and a control dog (lower row).

HE staining coronal sections show general structural changes of the spinal cord tissue after SCI. Extensive necrosis and prominent cavitation boundary to the scar predominates at the epicenter in the control dog (B1,B2), while they are much less appreciable in Canine 2 of the AFG group (A1,A2). Regenerated, aligned fibers are noted adjacent to the scar (arrow) in Canine 2. Masson staining also displays the regular arrangements of myelinated nerve fibers (A3), in contrast to the heavy collagen deposits by the green staining in the Control (B3). Immunofluorescence for NF-160 (green color) and GAP-43 (red color) shows positive expression of neurofilament-160 on the axons (A4) and growth-associated protein on the axons (A5) in canine 2, demonstrating the regeneration of the fibers. Scattered and slight expression of NF-160 is seen in the section of the control dog (B4), but no presence of positive expression of GAP-43 is found (B5). The merged images are presented as A6 and B6.