Figure 3

Cimetidine partially rescues impaired axonal regeneration in irf8 mutant zebrafish. A: Representative images of the lateral view of the injury site in cimetidine- and DMSO-treated larvae are shown. An axonal connection across the injury is visualized with DsRed, expressed under a neuronal promoter. Presence of an axonal bridge is indicated in the images. B: Quantification by scoring of animals for the presence of an axonal bridge indicates that Cimetidine increases the proportion of irf8 mutant larvae with an axonal bridge (two-way ANOVA, interaction effect F(1, 16) = 10.86, p* = 0.0046; Tukey's multiple comparison test, irf8 mutant, DMSO vs irf8 mutant, cimetidine p* = 0.0215, irf8, DMSO vs wt, DMSO p** = 0.0019, irf8, DMSO vs wt, cimetidine p* = 0.0295), but does not affect wild-type regeneration. C: Measuring the thickness of the axonal bridge yielded similar results for the experimental groups (two-way ANOVA, interaction effect F(1, 125) = 11.60, p*** = 0.0009; Tukey's multiple comparison test, irf8 mutant, DMSO vs irf8 mutant, cimetidine p* = 0.0112, irf8 mutant, DMSO vs wt, DMSO p** = 0.0074). Scale bar: 100 µm