Mice positive for the transgene (YFP+) were anesthetized with pentobarbital (90mg/kg; IP) and the common fibular (CF) nerve was exposed and cut with sharp scissors. The cut nerve was then repaired with a short (3 mm) segment of the CF nerve obtained from a WT littermate of the host mouse that was negative for the transgene. This nerve allograft and the cut ends of the CF nerve in the host mouse were carefully arranged on a short length of Gore-Tex tubing that had been cut in half longitudinally.