Axonal regeneration by PNG + aFGF treatment. A, Representative confocal images of 5-HT immunostaining in the PNG + aFGF group showing several regenerated 5-HT fibers (red) growing into the caudal end of the spinal cord. The caudal spinal cord interface is demarcated by a white line. Scale bar, 200 μm. B, C, Higher-magnification images from A show identified 5-HT fibers (red, arrow) at different locations within the caudal end of the spinal cord. Scale bar, 40 μm. D, In the Tx-only group, 5-HT fibers (red) can be identified in the rostral cord (identified by GFAP, green) but not entering the lesion cavity. The rostral spinal cord interface is demarcated by a white line. Scale bar, 500 μm. * indicates the cavity formation in the rostral cord. E, Higher-magnification images from D show identified 5-HT fibers (red, arrow) at different locations within the rostral end of the spinal cord. Scale bar, 200 μm. F, Representative confocal images of TH immunostaining in the PNG + aFGF group showing several regenerated TH fibers (red) growing into the caudal end of the spinal cord. The caudal spinal cord interface is demarcated by a white line. Scale bar, 200 μm. G, H, Higher-magnification images from F show identified TH fibers (red, arrow) at different locations within the caudal end of the spinal cord. Scale bar, 40 μm. I, In the Tx-only group, TH fibers (red) can be identified at the rostral cord (identified by GFAP, green) but not entering the lesion cavity. The rostral spinal cord interface is demarcated by a white line. Scale bar, 500 μm. * indicates cavity formation in the rostral cord. J, Higher-magnification images from I show identified TH fibers (red, arrow) at different locations within the rostral end of the spinal cord. Scale bar, 200 μm.