Electromechanical role of fixed charge in the mammalian tectorial membrane

Roozbeh Ghaffari, Scott Page, Shirin Farrahi, Jonathan B. Sellon, Dennis M. Freeman

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The mammalian tectorial membrane (TM) is thought to play a purely mechanical role in stimulating cochlear sensory receptors, but the presence of glycosaminoglycans and associated fixed charge groups suggests that electromechanical properties also may be important. Here, we measure the fixed charge concentration of the TM (-7.1 mmol/L at physiological pH), and show that this concentration of fixed charge is sufficient to generate electrokinetic motions of the TM. Electrically-evoked TM motions were nanometer-scaled (5-200 nm), increased linearly with electric field amplitude (0.05-20 kV/m) and decreased with frequency (1-1000 Hz). This frequency dependence can be understood in terms of the interplay between electrophoresis and electro-osmosis. Although the electric fields applied in this study were large, they are comparable in amplitude to the electric fields generated near hair cell transduction channels. TM electrokinetics could thus play a role in the deflection of cochlear hair bundles in vivo.

Original languageEnglish (US)
Title of host publicationMechanics of Hearing
Subtitle of host publicationProtein to Perception - Proceedings of the 12th International Workshop on the Mechanics of Hearing
EditorsDavid P. Corey, K. Domenica Karavitaki
PublisherAmerican Institute of Physics Inc.
Volume1703
ISBN (Electronic)9780735413504
DOIs
StatePublished - Dec 31 2015
Event12th International Workshop on the Mechanics of Hearing: Protein to Perception - Cape Sounio, Greece
Duration: Jun 23 2014Jun 29 2014

Other

Other12th International Workshop on the Mechanics of Hearing: Protein to Perception
CountryGreece
CityCape Sounio
Period6/23/146/29/14

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Ghaffari, R., Page, S., Farrahi, S., Sellon, J. B., & Freeman, D. M. (2015). Electromechanical role of fixed charge in the mammalian tectorial membrane. In D. P. Corey, & K. D. Karavitaki (Eds.), Mechanics of Hearing: Protein to Perception - Proceedings of the 12th International Workshop on the Mechanics of Hearing (Vol. 1703). [080001] American Institute of Physics Inc.. https://doi.org/10.1063/1.4939392