Figure 5

Figure 5

Inhibition of Src-family kinases reduced macrophage entry into injured neuromasts. Larval zebrafish were treated in 20 μM PP2, an inhibitor of several Src kinases. Control fish were treated in parallel with 0.1% DMSO. After 1 h pretreatment, neomycin was added to the water of both treatment groups (for a final concentration of 100 μM), and all specimens were euthanized and fixed after 30 min of neomycin exposure. (A–C) Single z-section images taken from 15 μm-depth confocal stacks. Arrows in panel (B) indicate macrophage phagocytosis of dying hair cells. (D–F) Quantification of macrophage activity. Normal numbers of macrophages were present near neuromasts L4/5 in all fish (D). Fish that were treated with 0.1% DMSO displayed a normal macrophage response to neomycin injury, but pretreatment with PP2 resulted in fewer macrophage contacts with dying hair cells (E) and reduced numbers of phagocytic events (F). Data were obtained from 34 fish for each treatment group/time point.