Figure 7.

Munc13 deletion promotes axon regeneration following adult CNS injury

(A) Multiphoton tile scan of GFP⁺ sensory axons (yellow) and GFAP⁺ astrocytes (blue) in the unsectioned spinal cord after complete dorsal column SCI in the given conditions. R, rostral; C, caudal. Asterisks indicate lesion centers. Scale bar, 200 μm.

(B) Quantification of (A). Scatterplot with means; ^∗∗∗p < 0.001, ^∗∗p < 0.01 by permutation test. n = 11 animals per group.

(C) Scheme of VGCC activation, presynaptic Ca²⁺ influx, and vesicle release.

(D) Representative fluorescence images of Tuj1 (red) and GFP/Cre-GFP (cyan) immunolabeled DRG neurons from Munc13-1^fl/flMunc13-2^KO/KOMunc13-3^KO/KO mice administered AAV-GFP or AAV-Cre-GFP and cultured for 24 h in the presence of DMSO, KCl (40 mM), Roscovotine (20 μM), or GV-58 (20 μM). Scale bar, 200 μm.

(E and F) Length of the longest axon (E) and branching frequency (F) of AAV-GFP⁺ neurons in (D). Values are plotted as mean ± SEM; ^∗∗∗p < 0.001 GFP DMSO versus GFP KCl, GFP Roscovotine, GFP GV-58 in (E) and ^∗∗p < 0.01 GFP DMSO versus GFP KCl, ^∗p < 0.05 GFP DMSO versus GFP Roscovotine, GFP DMSO versus GFP GV-58 in (F) by one-way ANOVA followed by Tukey’s post hoc test; n = 72 GFP DMSO, 86 GFP GV-58, 37 GFP KCl, 53 GFP Roscovotine-treated neurons from 3 independent experiments.

(G and H) Length of the longest axon (G) and branching frequency (H) of AAV-Cre-GFP⁺ neurons in (D). Values are plotted as mean ± SEM n = 82 Cre-GFP DMSO, 92 Cre-GFP GV-58, 48 Cre-GFP KCl, 23 Cre-GFP Roscovotine-treated neurons from 3 independent experiments.