FIG. 5.

Quantification of donor neurite outgrowth. A longitudinal section of the cervical spinal cord through the intermediate gray matter, immunohistochemically stained for GFP can be seen in (A). The transplant epicenter (green) has been overexposed so that GFP⁺ neurites projecting throughout the spinal cord can be visualized. High-magnification images of GFP⁺ neurites using lower, appropriate exposures were taken at 4-mm intervals along the length of the entire section, beginning at the rostral and caudal borders of the transplant and excluding GFP⁺ neurons. These images spanning the entire width of the cord were used to quantify the total area of GFP⁺ fibers (B). Outgrowth was measured in three sections per animal to include the dorsal horns (blue), intermediate gray (orange), and ventral horns (gray). Column graphs represent the average outgrowth at each distance in n = 4 animals with standard deviation. Statistical significance is marked by asterisks (p < 0.05). Scales are as indicated. GFP, green fluorescent protein. Color image is available online at www.liebertpub.com/neu