Nox inhibitors decrease neurite outgrowth in cultured zebrafish RGCs. A, Cultured zebrafish RGC neuron from a 36 hpf Tg(ath5:GFP) embryos shown in differential interference contrast at 0 min and 30 min later (A′). Scale bar, 10 μm. B, Different neuron in the presence of 0.05 μm celastrol and 30 min later (B′). Axon continued to grow, although not as fast as in control condition. C, Graph of neurite outgrowth in response to 0.1% DMSO (control) or increasing concentrations of celastrol. Numbers in parentheses indicate the number of cells analyzed. Graphs show mean ± SEM. Only 0.5 μm celastrol reduced neurite outgrowth rate significantly compared with control (p = 0.009; unpaired Student's t test). D, Graph of neurite outgrowth in response to 0.1% DMSO (control) or different concentrations of VAS2870. Only 1 μm VAS2870 reduced neurite outgrowth rate significantly compared with control condition (p = 0.0019; unpaired Student's t test).