Fig. 4

Dexamethasone exposure did not alter the number of afferent synapses in neuromast hair cells. A–D Representative maximum intensity projection images of 7 dpf pLL neuromasts, with hair cell presynaptic ribbons labeled via CtBP antibody (magenta), post-synaptic densities labeled via MAGUK antibody (green), and hair cell nuclei labeled with DAPI (blue). Neuromasts were either unlesioned (A, B) or lesioned with CuSO₄ (C, D), then allowed to regenerate for 48 h while exposed to DMSO (carrier) (A, C) or dexamethasone (B, D). E Scatter plots with mean and SEM bars showing no significant difference in the number of intact synapses in dexamethasone-treated fish, compared to DMSO controls for both lesioned and intact neuromasts. Each dot represents a single neuromast on an individual fish. Notably, a significantly greater number of intact synapses per hair cell were observed in regenerating neuromasts relative to neuromasts that were not lesioned (adjusted ***P < 0.001 (DMSO), *P < 0.05 (Dex)). N = 5–10 fish per condition per trial; 4 experimental trials