title: Gentamicin is ototoxic to all hair cells in the fish lateral line system.
abstract: Hair cells of the lateral line system in fish may differ in their susceptibility to damage by aminoglycoside antibiotics. Gentamicin has been reported to damage hair cells within canal neuromasts, but not those within superficial neuromasts. This finding, based on SEM imaging, indicates a distinction in the physiology of hair cells between the two classes of neuromast. Studies concerned with the individual roles of canal and superficial neuromasts in behavior have taken advantage of this effect in an attempt to selectively disable canal neuromasts without affecting superficial neuromast function. Here we present an experimental test of the hypothesis that canal neuromasts are more vulnerable to gentamicin than superficial neuromasts. We measured the effect of gentamicin exposure on hair cells using vital stains (DASPEI and FM1-43) in the neuromasts of Mexican blind cave fish (Astyanaxfasciatus) and zebrafish (Daniorerio). Contrary to the findings of prior studies that used SEM, gentamicin significantly reduced dye uptake by hair cells of both canal and superficial neuromasts in both species. Therefore, lateral line hair cells of both neuromast types are vulnerable to gentamicin ototoxicity. These findings argue for a re-evaluation of the results of studies that have used gentamicin to differentiate the roles of the two classes of neuromast in fish behavior.
authors.affiliation: Department of Ecology & Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA. wvantrum@uci.edu
authors.forename: William J
authors.initials: WJ
authors.lastname: Van Trump
authors.forename: Sheryl
authors.initials: S
authors.lastname: Coombs
authors.forename: Kyle
authors.initials: K
authors.lastname: Duncan
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: McHenry
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001522:Behavior, Animal / Q000502:physiology; D005399:Fishes / Q000502:physiology*; D005839:Gentamicins / Q000494:pharmacology*; D006198:Hair Cells, Auditory / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D053403:Lateral Line System / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D023421:Models, Animal; D015027:Zebrafish / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins