Fig. 5: High-resolution mapping of regenerative capacity across the length of the Mauthner axon.

a Targeted laser-induced injury allows to specifically injure the Mauthner axon at specific points along its length, starting very close to the soma. Regrowth can then be monitored over several days and compared with axon length in untreated siblings (control). b Absolute regrowth Δ on 4 dpi across all injury distances. Data are reasonably well described by a logarithmic Gaussian fit (R² = 0.66), with an optimum regenerative efficiency at an injury distance of about 258 ± 19 μm, i.e., at about 10% of total axon length. c We also considered relative regrowth (100*Δ/Δ′), i.e., absolute regrowth normalized to average fictive regrowth Δ′ (for a virtual injury at the same distance) in siblings of equal age. Relative regrowth also shows the clear dependence of regeneration on the soma-distance and the decline at large distances (R² = 0.49, with optimum regenerative efficiency at 438 ± 46 μm). b, c Significant differences, denoted by different letters, were estimated with the Kruskal–Wallis test followed by Dunn’s multiple comparison test (p < 0.0001). Circles depict mean ± SEM (N = 10–16).