Fig. 1

Male and female B6 (WT) mice have indistinguishable DRG macrophage accumulation and activation, and conditioned and unconditioned in vivo regeneration. A Diagram of our in vivo conditioning lesion (CL) and regeneration paradigm. B Macrophage quantification in Naïve, 2 day post-crush (Sh CL), and 9 day post-transection plus 2 day post-crush (CL) DRGs from male and female mice. Macrophages were quantified as the percent area stained by anti-CD68. Means were compared with a two-way ANOVA followed by Tukey’s post-hoc tests. C–H Representative images of macrophages in the cell body area of L4 DRGs from the indicated sex and injury condition. Scale bar is 50 μm. I Axon regeneration expressed as the fraction of axons relative to the crush site every 200 µm. Each point is the mean fraction ± SEM. Pairs of curves were compared using non-linear regression assuming one phase decay, initial Y = 1, and the plateau = 0 and significance was determined by comparing the decay constants of the fitted curves. J–M Representative images of regenerating axons stained for SCG10, a marker of regenerating sensory axons. Unconditioned growth (J, K), representing neuron intrinsic regeneration rate, and conditioned growth (L, M) were the same between sexes. Conditioned growth was increased compared to unconditioned growth in both sexes. 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 site. Scale bar is 500 μm. n = 10 for all groups and * indicates significance differences (**p < 0.01, ***p < 0.001) between indicated means