Reticular lamina and basilar membrane vibrations in living mouse cochleae

Tianying Ren, Wenxuan He, David Kemp

Research output: Contribution to journalArticle

45 Scopus citations

Abstract

It is commonly believed that the exceptional sensitivity of mammalian hearing depends on outer hair cells which generate forces for amplifying sound-induced basilar membrane vibrations, yet how cellular forces amplify vibrations is poorly understood. In this study, by measuring subnanometer vibrations directly from the reticular lamina at the apical ends of outer hair cells and from the basilar membrane using a custom-built heterodyne low-coherence interferometer, we demonstrate in living mouse cochleae that the soundinduced reticular lamina vibration is substantially larger than the basilar membrane vibration not only at the best frequency but surprisingly also at low frequencies. The phase relation of reticular lamina to basilar membrane vibration changes with frequency by up to 180 degrees from ∼135 degrees at low frequencies to ∼-45 degrees at the best frequency. The magnitude and phase differences between reticular lamina and basilar membrane vibrations are absent in postmortem cochleae. These results indicate that outer hair cells do not amplify the basilar membrane vibration directly through a local feedback as commonly expected; instead, they actively vibrate the reticular lamina over a broad frequency range. The outer hair cell-driven reticular lamina vibration collaboratively interacts with the basilar membrane traveling wave primarily through the cochlear fluid, which boosts peak responses at the best-frequency location and consequently enhances hearing sensitivity and frequency selectivity.

Original languageEnglish (US)
Pages (from-to)9910-9915
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume113
Issue number35
DOIs
StatePublished - Aug 30 2016

Keywords

  • Cochlea
  • Cochlear amplifier
  • Hearing
  • Interferometry
  • Outer hair cells

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Reticular lamina and basilar membrane vibrations in living mouse cochleae'. Together they form a unique fingerprint.

  • Cite this