Department of Ecology & Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA.
Hear Res. 2010 Mar;261(1-2):42-50. doi: 10.1016/j.heares.2010.01.001. Epub 2010 Jan 7.
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.
鱼类侧线系统的毛细胞在对氨基糖苷类抗生素的敏感性上可能存在差异。庆大霉素已被报道会损伤神经丘中的毛细胞，但不会损伤表皮神经丘中的毛细胞。这一基于扫描电子显微镜（SEM）成像的发现，表明两种神经丘中的毛细胞在生理学上存在区别。在关注神经丘在行为中的个体作用的研究中，人们利用了这一效应，试图选择性地使神经丘失能，而不影响表皮神经丘的功能。在这里，我们通过实验检验了一个假设，即神经丘比表皮神经丘更容易受到庆大霉素的影响。我们使用活体染料（DASPEI 和 FM1-43）测量了庆大霉素暴露对墨西哥盲眼洞穴鱼（Astyanax fasciatus）和斑马鱼（Danio rerio）神经丘中毛细胞的影响。与先前使用 SEM 的研究结果相反，庆大霉素显著降低了两种物种中神经丘中毛细胞对染料的摄取。因此，两种神经丘类型的侧线毛细胞都容易受到庆大霉素耳毒性的影响。这些发现表明，需要重新评估那些使用庆大霉素来区分鱼类行为中两种神经丘作用的研究结果。
