The Basilar Membrane Acts as a Passive Support Structure at the Cochlear Apex
2015 (English)In: MECHANICS OF HEARING: PROTEIN TO PERCEPTION, AMER INST PHYSICS , 2015, Vol. 1703, no 040006Conference paper (Refereed)Text
The precise mechanical behavior of the basilar membrane (BM) at low frequencies is still unknown. To address this issue we use an in vitro preparation of the guinea pig temporal bone to investigate the mechanical behaviour of the organ of Corti at the apex of the cochlea. Confocal laser interferometry is used to record the nanometre displacements of both Hensens cells (HeC) and the BM in response to sound and electrical stimulation. We show that at low frequencies, the BM exhibits greatly reduced sound-evoked movement (similar to 35dB less) and no current-evoked movement, when compared to the HeC at the same position along the spiral. The BM best frequency is found to be an average of 52Hz (0.35 octave) higher than the HeC best frequency. In addition, we demonstrate that BM motion is not affected by inhibition of somatic electromotility or by blocking the mechanoelectrical transduction channels. We therefore propose that the BM primarily acts as a passive support structure at the cochlear apex. We suggest that the micromechanics of the cochlea that are vital to low-frequency amplification and frequency selectivity take place predominantly at the surface of the organ of Corti.
Place, publisher, year, edition, pages
AMER INST PHYSICS , 2015. Vol. 1703, no 040006
, AIP Conference Proceedings, ISSN 0094-243X
IdentifiersURN: urn:nbn:se:liu:diva-127080DOI: 10.1063/1.4939340ISI: 000372065400027ISBN: 978-0-7354-1350-4OAI: oai:DiVA.org:liu-127080DiVA: diva2:919325
12th International Workshop on the Mechanics of Hearing