Lateral line hair cell maturation is a determinant of aminoglycoside susceptibility in zebrafish (Danio rerio)

Developmental differences in hair cell susceptibility to aminoglycoside-induced cell death has been observed in multiple species. Increased sensitivity to aminoglycosides has been temporally correlated with the onset of mechanotransduction-dependent activity. We have used in vivo fluorescent vital dye markers to further investigate the determinants of aminoglycoside induced hair cell death in the lateral line of zebrafish (Danio rerio). Labeling hair cells of the lateral line in vivo with the dyes FM 1-43, To-Pro-3, and Yo-Pro-1 served as reliable indicators of hair cell viability. Results indicate that hair cell maturation is a determinant of developmental differences in susceptibility. The age dependent differences in susceptibility to aminoglycosides are independent of the onset of mechanotransduction-dependent activity as measured by FM 1-43 uptake and independent of hair cell ability to take up fluorescently conjugated aminoglycosides.