Basilar Membrane and Tectorial Membrane Stiffness

Authors: I U Teudt C P Richter

Publish Date: 2014/05/28

Volume: 15, Issue: 5, Pages: 675-694

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Abstract

The mouse has become an important animal model in understanding cochlear function Structures such as the tectorial membrane or hair cells have been changed by gene manipulation and the resulting effect on cochlear function has been studied To contrast those findings physical properties of the basilar membrane BM and tectorial membrane TM in mice without gene mutation are of great importance Using the hemicochlea of CBA/CaJ mice we have demonstrated that tectorial membrane TM and basilar membrane BM revealed a stiffness gradient along the cochlea While a simple spring mass resonator predicts the change in the characteristic frequency of the BM the spring mass model does not predict the frequency change along the TM Plateau stiffness values of the TM were 06 ± 05 02 ± 01 and 009 ± 009 N/m for the basal middle and upper turns respectively The BM plateau stiffness values were 37 ± 22 12 ± 12 and 05 ± 05 N/m for the basal middle and upper turns respectively Estimations of the TM Young’s modulus in kPa revealed 243 ± 252 for the basal turns 51 ± 45 for the middle turns and 19 ± 16 for the apical turns Young’s modulus determined at the BM pectinate zone was 768 ± 72 239 ± 306 and 94 ± 62 kPa for the basal middle and apical turns respectively The reported stiffness values of the CBA/CaJ mouse TM and BM provide basic data for the physical properties of its organ of CortiThis work was supported by the American Hearing Research Foundation the Hugh Knowles Center the National Science Foundation IBN077476 and IBN0415901 and the NIH DC0008944 to MAC The authors thank Dr Peter Dallos for providing equipment and support to accomplish the experiments and for feedback on an earlier version of the manuscript

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