(A and C) Raphespinal axon sprouting in WT animals. Representative image of raphespinal fibers stained for 5HT in the spinal ventral horn. Coronal sections of cervical (A) and lumbar (C) were from vehicle- and J113397-treated mice at 72 days after hemisection. Scale bar, 100 μm. (B and D) Quantification of 5HT+ fiber density in WT animals. Means ± SE. n = 7 vehicle- injected mice and n = 7 J113397-injected mice. #No significant difference (B), *P < 0.05 (D), Student’s two-tailed t test. (E and G) Representative image of raphespinal fibers stained for 5HT in the spinal ventral horn. Coronal sections of cervical (E) and lumbar (G) were from vehicle- and J113397-treated mice from each genotype at 98 days after overhemisection. Scale bar, 100 μm. (F and H) Quantification of 5HT+ fiber density. Means ± SE. n = 14 mice for each group, #no significant differences (F), **P < 0.01, ***P < 0.005 (H), one-way ANOVA followed by Tukey’s test.