Mechanosensitive channels in the lateral wall can enhance the cochlear outer hair cell frequency response

Alexander A. Spector, Aleksander S. Popel, Ruth Anne Eatock, William E. Brownell

Research output: Contribution to journalArticle

Abstract

We present the results of a modeling study on the impact of mechanosensitive channels in the lateral wall of the outer hair cell on the cell frequency response. The model includes the electrical properties of the cell membrane, piezoelectricity associated with a membrane motor mechanism, and mechanosensitive channels in the cell lateral wall. The outer hair cell is loaded by the vibrating basilar and tectorial membranes, and this loading generates strain in the lateral wall. Our analysis reveals a property, the strain rate sensitivity, that, in concert with the piezoelectric effect, can enhance the cell frequency response. We discuss possible viscoelastic-type mechanisms of the channel's strain rate sensitivity that is consistent with the organization of the composite cell lateral wall. The parameters of our model are chosen on the basis of the previously estimated electrical and piezoelectric properties as well as typical conductance and density of the mechanosensitive channels in cells. We found that the strain rate sensitivity of the channels can result in receptor potentials greater than those predicted by the RC (resistance and capacitance) analysis. The effect of the channels is especially significant in an intermediate range of sound frequencies, and the channel-related gain is up to 3-4 times between 3 and 15 kHz.

Original languageEnglish (US)
Pages (from-to)991-1002
Number of pages12
JournalAnnals of biomedical engineering
Volume33
Issue number8
DOIs
StatePublished - Nov 1 2005

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Keywords

  • Active hearing
  • Electromotility
  • Membrane potential
  • Piezoelectric effect
  • Strain rate
  • Viscoelasticity

ASJC Scopus subject areas

  • Biomedical Engineering

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