Extracellular Ca2+ and Mg2+ modulate aminoglycoside blockade of mechanotransducer channel-mediated Ca2+ entry in zebrafish hair cells: An in vivo study with the SIET

Li Yih Lin, Wei Pang, Wei Min Chuang, Giun Yi Hung, Yuan Hsiang Lin, Jiun Lin Horng

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Zebrafish lateral-line hair cells are an in vivo model for studying hair cell development, function, and ototoxicity. However, the molecular identification and properties of the mechanotransducer (MET) channel in hair cells are still controversial. In this study, a noninvasive electrophysiological method, the scanning ion-electrode technique (SIET), was applied for the first time to investigate properties of MET channels in intact zebrafish embryos. With the use of a Ca2+-selective microelectrode to deflect hair bundles and simultaneously record the Ca2+ flux, the inward Ca2+ flux was detected at stereo cilia of hair cells in 2- to ~4-day postfer-tilization embryos. Ca2+ influx was blocked by MET channel blockers (BAPTA, La3+, Gd3+, and curare). In addition, 10 μM amino glycoside antibiotics (neomycin and gentamicin) were found to effectively block Ca2+ influx within 10 min. Elevating the external Ca2+ level (0.2-2 mM) neutralized the effects of neomycin and gentamicin. However, elevating the Mg2+ level up to 5 mM neutralized blockade by gentamicin but not by neomycin. This study demonstrated MET channel-mediated Ca2+ entry at hair cells and showed that the SIET to be a sensitive approach for functionally assaying MET channels in zebrafish.

Original languageEnglish
JournalAmerican Journal of Physiology - Cell Physiology
Volume305
Issue number10
DOIs
Publication statusPublished - Nov 15 2013

Keywords

  • Aminoglycoside
  • Hair cell
  • MET channel
  • Neuromast
  • SIET

ASJC Scopus subject areas

  • Cell Biology
  • Physiology

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