(A) The selected donor nerves were both dissected in a right forelimb and placed in a conduit reservoir filled with Fast-Blue (UN) and Fluoro-Ruby (AIN), respectively, for 1 hr. Wet sterile swabs were placed above the surgical site to prevent the tissue from drying and the fluorescent dyes from bleaching. (B) Spinal cord section C8-Th1. Labeled AIN (orange) and UN motoneuron pool (blue). (C) A Kruskal-Wallis H test was conducted to determine if there were differences in labeled motor neuron count between the three groups with different treatment: control (n=7), SNT (n=15), and DNT (n=15). Distributions of motor neuron count were not similar for all groups, as assessed by visual inspection of a boxplot. The mean ranks of motor neuron count were statistically significantly different between groups, χ2(2)=11.147, p=0.004. Subsequently, pairwise comparisons were performed using Dunn’s (1964) procedure with a Bonferroni correction for multiple comparisons. Adjusted p-values are presented. This post hoc analysis revealed statistically significant differences in labeled motor neuron count between the SNT (mean rank=11.90) and DNT (mean rank=24.67; *p=0.004) group, but not between the control group (mean rank=22.07) or any other group combination. DNT, double nerve transfer; GM, grey matter; SNT, single nerve transfer; WM, white matter.