Fig. 1

Dorsal root ganglion (DRG) sensory neurons are ineffective at regrowing central branch axons following axotomy. (a) Diagram of a larval zebrafish DRG at 3 days postfertilization (dpf) with central branch axotomy (CBA) laser ablation paradigm (D, dorsal; A, anterior). (b) In vivo, time-lapse imaging of a Tg(ngn1:gfp;sox10:nls-eos) DRG at 3 dpf before (Pre-injury) and post-CBA (?0 hours post-injury [hpi]) with fluorescently labeled sensory neuron (asterisk; neurite tip indicated by arrow), satellite glial cell nuclei (white arrowheads), and SC nuclei (open arrowhead). Spinal cord boundary indicated by dashed line. (c) Percent of DRGs with successful or unsuccessful central branch regrowth post-CBA (n = 39 DRGs from 22 fish). (d) Number of new dorsal neurite outgrowths per DRG post-CBA. (e) Quantification of time post-CBA at which the first dorsal neurite forms and initiates growth from the sensory neuronal soma (n = 16 neurites from 11 fish; dashed line, mean: 2.77 ± 1.66 h post-CBA). (f) Survival curves of primary (solid line) and secondary (dashed line) neurite longevity. Vertical lines mark the time (h) at which neurite survival probability is 50% (n = 30 neurites from 11 fish; mean: 4.91 ± 5.15 h; log-rank test, nsp >.05). Scale bar: 10 ?m.