Figure 5

Neutrophil recruitment induced by nerve neurectomy. (a-f) A larva obtained from a cross of TgBAC(neurod:EGFP) and Tg(lyz:DsRED2) transgenic fish labels the posterior lateral line nerve in green and leukocytes in red. (a) Control larva showing an intact lateral line nerve and few leukocytes near the nerve. One hour after lateral line nerve neurectomy (b), leukocytes migrate and accumulate at the lesion site (b and c). From 6 hpi, the number of recruited leukocytes decreases and resolution of inflammation takes place. (d-f). The number of recruited leukocytes continues to decrease as the lateral line nerve regenerates. (g) Quantification of average fluorescence intensity within a 50 μm radius surrounding the neurectomy site (panel b, dotted circle) shows leukocyte recruitment and subsequent inflammation resolution. Data are presented as average ± SEM from 17 larvae per condition from two independent experiments. Comparisons were performed by using a repeated measurement two-way ANOVA, with Bonferroni’s post test. ***, p < 0.001; ns, p > 0.05. Scale bar (a-f) 100 μm. hpi, hours post-injury; a. u., arbitrary units.