1G32 Numerical simulation of cochlear amplification mechanism caused by activity of the outer hair cell

2014 ◽  
Vol 2014.26 (0) ◽  
pp. 233-234
Author(s):  
Hideyuki MOCHIZUKI ◽  
Takuji KOIKE
Keyword(s):  
Numerical Simulation ◽  
Hair Cell ◽  
Outer Hair Cell ◽  
Cochlear Amplification ◽  
Amplification Mechanism

An outer hair cell-powered global hydromechanical mechanism for cochlear amplification

2021 ◽  
pp. 108407
Author(s):  
Wenxuan He ◽  
George Burwood ◽  
Anders Fridberger ◽  
Alfred L. Nuttall ◽  
Tianying Ren
Keyword(s):  
Hair Cell ◽  
Outer Hair Cell ◽  
Cochlear Amplification

8H-18 Importance of outer hair cell coordinating movement for cochlear amplification

2011 ◽  
Vol 2010.23 (0) ◽  
pp. 283-284
Author(s):  
Sho SUZUKI ◽  
Michio MURAKOSHI ◽  
Hiroshi WADA
Keyword(s):  
Hair Cell ◽  
Outer Hair Cell ◽  
Cochlear Amplification

scholarly journals A gap-junction mutation in the mouse cochlea reveals cochlear amplification is driven by outer hair cell extracellular receptor potentials

2021 ◽  
Author(s):  
Snezana Levic ◽  
Victoria A Lukashkina ◽  
Patricio Simoes ◽  
Andrei N Lukashkin ◽  
Ian J Russell
Keyword(s):  
Hair Cell ◽  
Gap Junction ◽  
High Frequency ◽  
Outer Hair Cell ◽  
Stria Vascularis ◽  
Organ Of Corti ◽  
Receptor Potential ◽  
Wild Type ◽  
Hearing Sensitivity ◽  
Cochlear Amplification

Cochlear amplification, whereby cochlear responses to low-to-moderate sound levels are 31 amplified and compressed to loud sounds, is attributed to outer hair cell (OHC) electromotility 32 driven by voltage changes across the OHC basolateral membranes due to sound-induced 33 receptor-current modulation. Cochlear operation at high acoustic frequencies is enigmatic 34 because the OHC intracellular receptor potential (RP) is severely attenuated at these 35 frequencies. Clues to understanding the voltage control of OHC electromotility at different 36 frequencies was provided by measurements from CD-1 mice with an A88V mutation of the 37 gap-junction (GJ) protein connexin 30 (Cx30), which with Cx26, form heterogeneous GJs 38 between supporting cells in the organ of Corti (OoC) and stria vascularis. The A88V mutation 39 results in a smaller GJ conductance which may explain why the resistance across the OoC in 40 CD-1Cx30A88V/A88V mutants is higher compared with wild-type mice. The endocochlear 41 potential, which drives the OHC receptor current and, consequently, the OHC RPs, is smaller 42 in CD-1Cx30A88V/A88V mutants. Even so, their high-frequency hearing sensitivity equals that of 43 wild-type mice. Preservation of high-frequency hearing correlates with similar amplitude of 44 extracellular receptor potentials (ERPs), measured immediately adjacent to the OHCs. ERPs 45 are generated through OHC receptor current flow across the OoC electrical resistance, which 46 is larger in CD-1Cx30A88V/A88V than in wild-type mice. Thus, smaller OHC receptor currents 47 flowing across a larger OoC resistance in CD-1Cx30A88V/A88V mice may explain why their ERP 48 magnitudes are similar to wild-type mice. It is proposed that the ERPs, which are not subject 49 to low-pass electrical filtering, drive high-frequency cochlear amplification.

scholarly journals Prestin-Driven Cochlear Amplification Is Not Limited by the Outer Hair Cell Membrane Time Constant

Neuron ◽  
2011 ◽  
Vol 70 (6) ◽  
pp. 1143-1154 ◽  
Author(s):  
Stuart L. Johnson ◽  
Maryline Beurg ◽  
Walter Marcotti ◽  
Robert Fettiplace
Keyword(s):  
Cell Membrane ◽  
Hair Cell ◽  
Time Constant ◽  
Outer Hair Cell ◽  
Membrane Time Constant ◽  
Cochlear Amplification

scholarly journals Outer hair cell electromotility is low-pass filtered relative to the molecular conformational changes that produce nonlinear capacitance

2019 ◽  
Vol 151 (12) ◽  
pp. 1369-1385 ◽  
Author(s):  
Joseph Santos-Sacchi ◽  
Kuni H. Iwasa ◽  
Winston Tan
Keyword(s):  
Guinea Pig ◽  
Hair Cell ◽  
Frequency Response ◽  
Time Constant ◽  
Outer Hair Cell ◽  
Resting Potential ◽  
Nonlinear Capacitance ◽  
Cochlear Amplification ◽  
Low Pass ◽  
Length Changes

The outer hair cell (OHC) of the organ of Corti underlies a process that enhances hearing, termed cochlear amplification. The cell possesses a unique voltage-sensing protein, prestin, that changes conformation to cause cell length changes, a process termed electromotility (eM). The prestin voltage sensor generates a capacitance that is both voltage- and frequency-dependent, peaking at a characteristic membrane voltage (Vh), which can be greater than the linear capacitance of the OHC. Accordingly, the OHC membrane time constant depends upon resting potential and the frequency of AC stimulation. The confounding influence of this multifarious time constant on eM frequency response has never been addressed. After correcting for this influence on the whole-cell voltage clamp time constant, we find that both guinea pig and mouse OHC eM is low pass, substantially attenuating in magnitude within the frequency bandwidth of human speech. The frequency response is slowest at Vh, with a cut-off, approximated by single Lorentzian fits within that bandwidth, near 1.5 kHz for the guinea pig OHC and near 4.3 kHz for the mouse OHC, each increasing in a U-shaped manner as holding voltage deviates from Vh. Nonlinear capacitance (NLC) measurements follow this pattern, with cut-offs about double that for eM. Macro-patch experiments on OHC lateral membranes, where voltage delivery has high fidelity, confirms low pass roll-off for NLC. The U-shaped voltage dependence of the eM roll-off frequency is consistent with prestin’s voltage-dependent transition rates. Modeling indicates that the disparity in frequency cut-offs between eM and NLC may be attributed to viscoelastic coupling between prestin’s molecular conformations and nanoscale movements of the cell, possibly via the cytoskeleton, indicating that eM is limited by the OHC’s internal environment, as well as the external environment. Our data suggest that the influence of OHC eM on cochlear amplification at higher frequencies needs reassessment.

scholarly journals Prestin-Based Outer Hair Cell Motility Is Necessary for Mammalian Cochlear Amplification

Neuron ◽  
2008 ◽  
Vol 58 (3) ◽  
pp. 333-339 ◽  
Author(s):  
Peter Dallos ◽  
Xudong Wu ◽  
Mary Ann Cheatham ◽  
Jiangang Gao ◽  
Jing Zheng ◽  
...  
Keyword(s):  
Hair Cell ◽  
Cell Motility ◽  
Outer Hair Cell ◽  
Outer Hair Cell Motility ◽  
Cochlear Amplification

scholarly journals Single particle cryo-EM structure of the outer hair cell motor protein prestin

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Carmen Butan ◽  
Qiang Song ◽  
Jun-Ping Bai ◽  
Winston J. T. Tan ◽  
Dhasakumar Navaratnam ◽  
...  
Keyword(s):  
Hair Cell ◽  
Outer Hair Cell ◽  
Sulfate Transporter ◽  
Transmembrane Segments ◽  
Cryo Electron Microscopy ◽  
Anion Transporter ◽  
Cochlear Amplification ◽  
Displacement Currents ◽  
Factor Antagonist ◽  
Putative Mechanism

AbstractThe mammalian outer hair cell (OHC) protein prestin (Slc26a5) differs from other Slc26 family members due to its unique piezoelectric-like property that drives OHC electromotility, the putative mechanism for cochlear amplification. Here, we use cryo-electron microscopy to determine prestin’s structure at 3.6 Å resolution. Prestin is structurally similar to the anion transporter Slc26a9. It is captured in an inward-open state which may reflect prestin’s contracted state. Two well-separated transmembrane (TM) domains and two cytoplasmic sulfate transporter and anti-sigma factor antagonist (STAS) domains form a swapped dimer. The transmembrane domains consist of 14 transmembrane segments organized in two 7+7 inverted repeats, an architecture first observed in the bacterial symporter UraA. Mutation of prestin’s chloride binding site removes salicylate competition with anions while retaining the prestin characteristic displacement currents (Nonlinear Capacitance), undermining the extrinsic voltage sensor hypothesis for prestin function.

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