QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, October 25, 2006, 26(43):10992-11000; doi:10.1523/JNEUROSCI.2188-06.2006

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (18) Citing Articles via Google Scholar Google Scholar Articles by Beurg, M. Articles by Fettiplace, R. Search for Related Content PubMed PubMed Citation Articles by Beurg, M. Articles by Fettiplace, R.

 Previous Article  |  Next Article 

Cellular/Molecular
A Large-Conductance Calcium-Selective Mechanotransducer Channel in Mammalian Cochlear Hair Cells

Maryline Beurg,¹ Michael G. Evans,² Carole M. Hackney,² and Robert Fettiplace³

¹Equipe Associée 3665 Université Victor Segalen Bordeaux 2, Institut National de la Santé et de la Recherche Médicale, Unité 587, Hôpital Pellegrin, 33076 Bordeaux, France, ²Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, Staffordshire ST5 5BG, United Kingdom, and ³Department of Physiology, University of Wisconsin Medical School, Madison, Wisconsin 53706

Correspondence should be addressed to Robert Fettiplace, 185, Medical Sciences Building, 1300 University Avenue, Madison, WI 53706. Email: fettiplace{at}physiology.wisc.edu

Sound stimuli are detected in the cochlea by opening of hair cell mechanotransducer (MT) channels, one of the few ion channels not yet conclusively identified at a molecular level. To define their performance in situ, we measured MT channel properties in inner hair cells (IHCs) and outer hair cells (OHCs) at two locations in the rat cochlea tuned to different characteristic frequencies (CFs). The conductance (in 0.02 mM calcium) of MT channels from IHCs was estimated as 260 pS at both low-frequency and mid-frequency positions, whereas that from OHCs increased with CFs from 145 to 210 pS. The combination of MT channel conductance and tip link number, assayed from scanning electron micrographs, accounts for variation in whole-cell current amplitude for OHCs and its invariance for IHCs. Channels from apical IHCs and OHCs having a twofold difference in unitary conductance were both highly calcium selective but were distinguishable by a small but significant difference in calcium permeability and in their response to lowering ionic strength. The results imply that the MT channel has properties possessed by few known candidates, and its diversity suggests expression of multiple isoforms.

Key words: auditory; calcium [Ca]; channel; cochlea; hair cell; mechanosensory; transduction

---

Received May 23, 2006; revised Sept. 10, 2006; accepted Sept. 11, 2006.

Correspondence should be addressed to Robert Fettiplace, 185, Medical Sciences Building, 1300 University Avenue, Madison, WI 53706. Email: fettiplace{at}physiology.wisc.edu

This article has been cited by other articles:

				A. Lelli, Y. Asai, A. Forge, J. R. Holt, and G. S. G. Geleoc Tonotopic Gradient in the Developmental Acquisition of Sensory Transduction in Outer Hair Cells of the Mouse Cochlea J Neurophysiol, June 1, 2009; 101(6): 2961 - 2973. [Abstract] [Full Text] [PDF]

				R. Stepanyan and G. I. Frolenkov Fast Adaptation and Ca2+ Sensitivity of the Mechanotransducer Require Myosin-XVa in Inner But Not Outer Cochlear Hair Cells J. Neurosci., April 1, 2009; 29(13): 4023 - 4034. [Abstract] [Full Text] [PDF]

				A. F. J. van Aken, M. Atiba-Davies, W. Marcotti, R. J. Goodyear, J. E. Bryant, G. P. Richardson, K. Noben-Trauth, and C. J. Kros TRPML3 mutations cause impaired mechano-electrical transduction and depolarization by an inward-rectifier cation current in auditory hair cells of varitint-waddler mice J. Physiol., November 15, 2008; 586(22): 5403 - 5418. [Abstract] [Full Text] [PDF]

				J. Ashmore Cochlear Outer Hair Cell Motility Physiol Rev, January 1, 2008; 88(1): 173 - 210. [Abstract] [Full Text] [PDF]

				E. A. Stauffer and J. R. Holt Sensory Transduction and Adaptation in Inner and Outer Hair Cells of the Mouse Auditory System J Neurophysiol, December 1, 2007; 98(6): 3360 - 3369. [Abstract] [Full Text] [PDF]

				M. Knirsch, N. Brandt, C. Braig, S. Kuhn, B. Hirt, S. Munkner, M. Knipper, and J. Engel Persistence of Cav1.3 Ca2+ Channels in Mature Outer Hair Cells Supports Outer Hair Cell Afferent Signaling J. Neurosci., June 13, 2007; 27(24): 6442 - 6451. [Abstract] [Full Text] [PDF]

				N. Michalski, V. Michel, A. Bahloul, G. Lefevre, J. Barral, H. Yagi, S. Chardenoux, D. Weil, P. Martin, J.-P. Hardelin, et al. Molecular Characterization of the Ankle-Link Complex in Cochlear Hair Cells and Its Role in the Hair Bundle Functioning J. Neurosci., June 13, 2007; 27(24): 6478 - 6488. [Abstract] [Full Text] [PDF]

				F. Mammano, M. Bortolozzi, S. Ortolano, and F. Anselmi Ca2+ Signaling in the Inner Ear Physiology, April 1, 2007; 22(2): 131 - 144. [Abstract] [Full Text] [PDF]

				S. Jia, P. Dallos, and D. Z. Z. He Mechanoelectric Transduction of Adult Inner Hair Cells J. Neurosci., January 31, 2007; 27(5): 1006 - 1014. [Abstract] [Full Text] [PDF]

				R. Ficarella, F. Di Leva, M. Bortolozzi, S. Ortolano, F. Donaudy, M. Petrillo, S. Melchionda, A. Lelli, T. Domi, L. Fedrizzi, et al. A functional study of plasma-membrane calcium-pump isoform 2 mutants causing digenic deafness PNAS, January 30, 2007; 104(5): 1516 - 1521. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help