Marcotti, W., Corns, L.F., Desmonds, T. et al. (3 more authors) (2014) Transduction without Tip Links in Cochlear Hair Cells Is Mediated by Ion Channels with Permeation Properties Distinct from Those of the Mechano-Electrical Transducer Channel. The Journal of Neuroscience, 34 (16). 5505 - 5514. ISSN 0270-6474
Abstract
Tip links between adjacent stereocilia are believed to gate mechano-electrical transducer (MET) channels and mediate the electrical responses of sensory hair cells. We found that mouse auditory hair cells that lack tip links due to genetic mutations or exposure to the Ca2� chelator BAPTA can, however, still respond to mechanical stimuli. These MET currents have unusual properties and are predominantly of the opposite polarity relative to those measured when tip links are present. There are other striking differences, for example, the channels are usually all closed when the hair cell is not stimulated and the currents in response to strong stimuli can be substantially larger than normal. These anomalous MET currents can also be elicited early in development, before the onset of mechano-electrical transduction with normal response polarity. Current–voltage curves of the anomalous MET currents are linear and do not show the rectification characteristic of normalMETcurrents. The permeantMETchannel blocker dihydrostreptomycin is two orders of magnitude less effective in blocking the anomalousMETcurrents. The findings suggest the presence of a large population ofMETchannels with pore properties that are distinct from those of normal MET channels. These channels are not gated by hair-bundle links and can be activated under a variety of conditions in which normal tip-link-mediated transduction is not operational.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2014 Marcotti et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | aminoglycoside antibiotics; cochlea; hair cell; mechano-electrical transduction |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Biomedical Science (Sheffield) |
Funding Information: | Funder Grant number Wellcome Trust WT091895MA |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 24 Jun 2014 14:48 |
Last Modified: | 24 Jun 2014 14:48 |
Published Version: | http://dx.doi.org/10.1523/JNEUROSCI.4086-13.2014 |
Status: | Published |
Publisher: | Society for Neuroscience |
Refereed: | Yes |
Identification Number: | 10.1523/JNEUROSCI.4086-13.2014 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:79520 |