Fig. 5

Conditioned and unconditioned in vivo regeneration is unaffected in all the conditional Ccl2 knockouts. Conditioned nerves (CL) were transected 7 days prior to the test lesion crush and allowed to regenerate for 2 days. Unconditioned nerves (Sh CL) were given a sham surgery on the day of the conditioning lesion and were then crushed 7 days later and allowed to regenerate for 2 days. A Axon regeneration expressed as the fraction of axons relative to the crush site every 100 μm. Each point is the mean fraction ± SEM. B Mean regeneration determined by integrating regenerating axon fluorescence to find the average axon length for each nerve. # Indicates a significant (p < 0.05) difference between the Sh CL (unconditioned) and CL (conditioned) regeneration within a genotype. There were no significant differences between genotypes within an injury condition. For A and B, the analysis ends at 3000 μm from the crush because that is the length of the shortest nerve segment. For A and B, the n are: Flox Sh = 9, Flox CL = 8, ACKO Sh = 10, ACKO CL = 9, PCKO Sh = 10, PCKO CL = 10, DCKO Sh = 10, DCKO CL = 8. One CL nerve was excluded from analysis of each of the Flox CL, ACKO CL, and DCKO CL groups for violating assumption 5 (see “Materials and methods”). C–G Representative images of regenerating nerves stained with SCG10. Unconditioned growth (C), representing neuron intrinsic regeneration rate, was the same amongst all genotypes. Conditioned growth (D–G) was also the same across genotypes and increased compared to unconditioned controls (compare to C). 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 is 500 μm