Frequency-dependent properties of the tectorial membrane facilitate energy transmission and amplification in the cochlea

Research output: Contribution to journalArticle

Abstract

The remarkable sensitivity, frequency selectivity, and dynamic range of the mammalian cochlea relies on longitudinal transmission of minuscule amounts of energy as passive, pressure-driven, basilar membrane (BM) traveling waves. These waves are actively amplified at frequency-specific locations by a mechanism that involves interaction between the BM and another extracellular matrix, the tectorial membrane (TM). From mechanical measurements of isolated segments of the TM, we made the important new (to our knowledge) discovery that the stiffness of the TM is reduced when it is mechanically stimulated at physiologically relevant magnitudes and at frequencies below their frequency place in the cochlea. The reduction in stiffness functionally uncouples the TM from the organ of Corti, thereby minimizing energy losses during passive traveling-wave propagation. Stiffening and decreased viscosity of the TM at high stimulus frequencies can potentially facilitate active amplification, especially in the high-frequency, basal turn, where energy loss due to internal friction within the TM is less than in the apex. This prediction is confirmed by neural recordings from several frequency regions of the cochlea.
Original languageEnglish
Pages (from-to)1357-1366
Number of pages10
JournalBiophysical Journal
Volume104
Issue number6
Publication statusPublished - 19 Mar 2013

Fingerprint Dive into the research topics of 'Frequency-dependent properties of the tectorial membrane facilitate energy transmission and amplification in the cochlea'. Together they form a unique fingerprint.

Cite this