Assessment of lateral line function: a potential technique for studies in ototoxicity

In zebrafish neuromast hair cells, the process of programmed cell death ototoxic damage is strikingly similar to that of degenerating hair cells of the mammalian organ of Corti. Therefore, in vivo zebrafish assays involving the lateral line have been developed for drug ototoxicity screening. This is accomplished by examination of canal neuromast morphology in treated larvae using fluorescent dyes. To-date however, physiological confirmation of lateral line dysfunction resulting from such ototoxins has not been reported in the scientific literature--neither for larval nor adult zebrafish. Here we describe a rapid, non-invasive far-field electrophysiological method for assessing lateral line function. We suggest that ototoxic and otoprotective agents identified in larval studies may be assessed using this tool in adult fish. In this way, potential drug candidates can be further screened en route to testing in mammalian models, before potential clinical trials begin.