» Articles » PMID: 39148291

Rate-dependent Cochlear Outer Hair Cell Force Generation: Models and Parameter Estimation

Overview
Journal Biophys J
Publisher Cell Press
Specialty Biophysics
Date 2024 Aug 16
PMID 39148291
Authors
Affiliations
Soon will be listed here.
Abstract

The outer hair cells (OHCs) of the mammalian cochlea are the mediators of an active, nonlinear electromechanical process necessary for sensitive, frequency-specific hearing. The membrane protein prestin conveys to the OHC a piezoelectric-like behavior hypothesized to actuate a high frequency, cycle-by-cycle conversion of electrical to mechanical energy to boost cochlear responses to low-level sound. This hypothesis has been debated for decades, with two key remaining issues: the influence of the rate dependence of conformal changes in prestin and the OHC transmembrane impedance. In this paper, we mainly focus on the rate dependence of the conformal change in prestin. A theoretical electromechanical model of the OHC that explicitly includes rate dependence of conformal transitions, viscoelasticity, and piezoelectricity. Using this theory, we show the influence of rate dependence and viscoelasticity on electromechanical force generation and transmembrane impedance. Furthermore, we stress the importance of using the correct mechanical boundary conditions when estimating the transmembrane capacitance. Finally, a set of experiments is described to uniquely estimate the constitutive properties of the OHC from whole-cell measurements.

References
1.
Corbitt C, Farinelli F, Brownell W, Farrell B . Tonotopic relationships reveal the charge density varies along the lateral wall of outer hair cells. Biophys J. 2012; 102(12):2715-24. PMC: 3379021. DOI: 10.1016/j.bpj.2012.04.054. View

2.
Adachi M, Iwasa K . Electrically driven motor in the outer hair cell: effect of a mechanical constraint. Proc Natl Acad Sci U S A. 1999; 96(13):7244-9. PMC: 22066. DOI: 10.1073/pnas.96.13.7244. View

3.
Dallos P, Wu X, Cheatham M, Gao J, Zheng J, Anderson C . Prestin-based outer hair cell motility is necessary for mammalian cochlear amplification. Neuron. 2008; 58(3):333-9. PMC: 2435065. DOI: 10.1016/j.neuron.2008.02.028. View

4.
Zhou W, Nam J . Probing hair cell's mechano-transduction using two-tone suppression measurements. Sci Rep. 2019; 9(1):4626. PMC: 6420497. DOI: 10.1038/s41598-019-41112-5. View

5.
Dimitriadis E, Chadwick R . Solution of the inverse problem for a linear cochlear model: a tonotopic cochlear amplifier. J Acoust Soc Am. 1999; 106(4 Pt 1):1880-92. DOI: 10.1121/1.427937. View