Mechanically and ATP-induced currents of mouse outer hair cells are independent and differentially blocked by d-tubocurarine

Elisabeth B Glowatzki, J. P. Ruppersberg, H. P. Zenner, A. Rüsch

Research output: Contribution to journalArticle

Abstract

Mechano-electrical transducer channels (MET) and ATP-gated ion channels (P2X receptors) of hair cells have several properties in common: they share the same location at the apex of the cell, both channels are non-selective for cations and blocked by aminoglycosides and pyrazinecarboxamides (amiloride-related compounds). In this study, we test the relationship and possible identity of these two channel types. Using whole-cell patch-clamp recordings of outer hair cells (OHCs) of the cultured neonatal mouse cochlea and a fluid jet to stimulate their hair bundles mechanically, we show that d- tubocurarine, a blocker of P2X2 receptors, blocks MET channels with a half- blocking concentration of 2.3 μM. In contrast, the K(D) for the P2X2 receptors was 90 μM and 84 μM measured in hair cells and Xenopus oocytes, respectively. When hair bundles of OHCs were simultaneously stimulated with saturating mechanical stimuli and superfused by 100-300 μM ATP, transducer currents and ATP-activated currents were elicited simultaneously. Their amplitudes were additive, however. We conclude that MET- and ATP-activated currents are mediated by two distinct channel populations in hair cells.

Original languageEnglish (US)
Pages (from-to)1269-1275
Number of pages7
JournalNeuropharmacology
Volume36
Issue number9
DOIs
StatePublished - Sep 1997
Externally publishedYes

Fingerprint

Outer Auditory Hair Cells
Tubocurarine
Transducers
Adenosine Triphosphate
Purinergic P2X2 Receptors
Pyrazinamide
Amiloride
Cochlea
Aminoglycosides
Xenopus
Ion Channels
Oocytes
Cations

Keywords

  • ATP-activated channel
  • Cochlea
  • d-tubocurarine
  • Hair cell
  • Mechano-electrical transducer channel
  • P2X receptor

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Drug Discovery
  • Pharmacology

Cite this

Mechanically and ATP-induced currents of mouse outer hair cells are independent and differentially blocked by d-tubocurarine. / Glowatzki, Elisabeth B; Ruppersberg, J. P.; Zenner, H. P.; Rüsch, A.

In: Neuropharmacology, Vol. 36, No. 9, 09.1997, p. 1269-1275.

Research output: Contribution to journalArticle

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