Fig. 2

The central process of sensory neurons shows enhanced regeneration after a peripheral CL in Ccr2 KO animals. A. Diagram showing the sciatic CL, dorsal root TLs and the time course used for the in vivo dorsal root regeneration assay performed on WT and Ccr2 KO animals. B-E. Representative images of regenerating dorsal roots immunostained for SCG10 in 40 μm sections. Unconditioned regeneration (B, D) shows that the poor intrinsic regenerative capacity of dorsal root axons is the same in both genotypes. Conditioned regeneration (CL; C, F) was also the same between genotypes and significantly increased compared to contralateral unconditioned roots. The dotted line indicates the center of the crush site which was considered to be 500 μm wide, and the solid line is 3000 μm from the crush. Scale bar = 500 μm. F. Axon regeneration quantified at 100 μm intervals as the fraction of regenerating axons relative to the axons in the 300 μm proximal to the crush site. The fraction of axons at each distance from the crush was calculated from ratios of SCG10 immunofluorescence. G. Mean regeneration distance calculated by integrating SCG10 immunofluorescent staining of regenerating axons. # indicates a significant (p < 0.05) difference between the Sh (unconditioned) and CL (conditioned) regeneration within a genotype. N = 7–8 per group