Retrograde labeling of motor and sensory tibial (TIB) neurons that grow axons from a donor TIB nerve into a recipient denervated common peroneal (CP) nerve and, of CP neurons that regenerate their axons after delayed CP nerve repair.

<p>In the first set of experiments (No Repair: <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127397#pone.0127397.t001" target="_blank">Table 1</a>) A. Fluorogold (FG) and fluororuby (FR) retrograde dyes were applied to the CP nerve stump 5 mm either side of 3.2 mm long cross-bridges in order to identify the TIB neurons that had grown axons through the cross-bridges into the recipient denervated CP nerve stump. B,C. In a second set of experiments (Repair, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0127397#pone.0127397.t001" target="_blank">Table 1</a>), 5 months after delayed repair of CP nerve, FG or FR was applied to the regenerated CP axons to enumerate the CP neurons that had regenerated through the denervated CP nerve stump ‘protected’ by 3 (B) and 9 (C) bridges, as examples. By cutting through the cross-bridges at the same time as the dye application, retrograde labelling was confined to only the CP neurons that had regenerated their axons through the cross-bridges (B,C).