Lifelong dynamic maintenance of stereocilia bundles in mammalian auditory hair cells

A. Catalina Vélez-Ortega; Gregory I. Frolenkov

doi:10.1016/bs.ctdb.2025.03.003

Lifelong dynamic maintenance of stereocilia bundles in mammalian auditory hair cells

A. Catalina Vélez-Ortega, Gregory I. Frolenkov

Research output: Chapter in Book/Report/Conference proceeding › Chapter › peer-review

Abstract

Our sense of hearing is initiated when sound-induced vibrations deflect specialized mechanosensory projections, stereocilia, emanating from the apical surface of the inner ear hair cells. Each hair cell has dozens of stereocilia organized into rows of increasing heights, forming a “hair” bundle. This “staircase” architecture of the stereocilia bundle is common for all vertebrate hair cells and essential for normal mechanosensitivity. Yet, the molecular mechanisms underlying its formation and lifelong maintenance in non-regenerating mammalian auditory hair cells represent a fascinating but yet puzzling problem for cell biology. Recent data demonstrating that stereocilia dimensions are controlled by the ionic current through mechanosensitive channels at the tips of stereocilia may help in solving this puzzle. The current chapter describes potential molecular mechanisms of stereocilia bundle formation and maintenance, as well as the mechanisms that optimize the mechanical properties of the hair bundle for effective mechanosensation.

Original language	English
Title of host publication	Current Topics in Developmental Biology
DOIs	https://doi.org/10.1016/bs.ctdb.2025.03.003
State	Accepted/In press - 2025

Publication series

Name	Current Topics in Developmental Biology
ISSN (Print)	0070-2153

Bibliographical note

Publisher Copyright:
© 2025

Funding

We thank Dr. Anna Lysakowski, Dr. Patricia M. Qui\u00F1ones, Dr. Shadan Hadi, Dr. Jonathan M. Grossheim, Ana I. L\u00F3pez-Porras, and Garett K. Davies for helping with sample preparation for electron microscopy images used in our illustrations. We also thank Dr. Peter G. Barr-Gillespie, Dr. Jocelyn F. Krey, Dr. Guy P. Richardson, and Dr. Doris K. Wu for their very insightful comments that helped us shape this manuscript. Relevant studies in the V\u00E9lez-Ortega and Frolenkov labs are supported by NIH/NIDCD grants R01DC021325 (A.C.V.O.), R01DC019054 (G.I.F.) and R01DC017147 (G.I.F.). FIB-SEM imaging was supported by NIH grant S10OD025130 (G.I.F.) and was performed at the University of Kentucky Electron Microscopy Center, which belongs to the National Science Foundation NNCI Kentucky Multiscale Manufacturing and Nano Integration Node, supported by ECCS-1121 1542174.

Funders	Funder number
National Institutes of Health (NIH)
National Institute on Deafness and Other Communication Disorders	R01DC021325, R01DC019054
National Science Foundation NNCI Kentucky Multiscale Manufacturing	ECCS-1121 1542174
G.I.F.	S10OD025130, R01DC017147

Keywords

Hair bundle stiffness
Hearing
Inner ear hair cells
Mechanotransduction
Stereocilia development

ASJC Scopus subject areas

Developmental Biology
Cell Biology

Access to Document

10.1016/bs.ctdb.2025.03.003

Cite this

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title = "Lifelong dynamic maintenance of stereocilia bundles in mammalian auditory hair cells",

abstract = "Our sense of hearing is initiated when sound-induced vibrations deflect specialized mechanosensory projections, stereocilia, emanating from the apical surface of the inner ear hair cells. Each hair cell has dozens of stereocilia organized into rows of increasing heights, forming a “hair” bundle. This “staircase” architecture of the stereocilia bundle is common for all vertebrate hair cells and essential for normal mechanosensitivity. Yet, the molecular mechanisms underlying its formation and lifelong maintenance in non-regenerating mammalian auditory hair cells represent a fascinating but yet puzzling problem for cell biology. Recent data demonstrating that stereocilia dimensions are controlled by the ionic current through mechanosensitive channels at the tips of stereocilia may help in solving this puzzle. The current chapter describes potential molecular mechanisms of stereocilia bundle formation and maintenance, as well as the mechanisms that optimize the mechanical properties of the hair bundle for effective mechanosensation.",

keywords = "Hair bundle stiffness, Hearing, Inner ear hair cells, Mechanotransduction, Stereocilia development",

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series = "Current Topics in Developmental Biology",

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N2 - Our sense of hearing is initiated when sound-induced vibrations deflect specialized mechanosensory projections, stereocilia, emanating from the apical surface of the inner ear hair cells. Each hair cell has dozens of stereocilia organized into rows of increasing heights, forming a “hair” bundle. This “staircase” architecture of the stereocilia bundle is common for all vertebrate hair cells and essential for normal mechanosensitivity. Yet, the molecular mechanisms underlying its formation and lifelong maintenance in non-regenerating mammalian auditory hair cells represent a fascinating but yet puzzling problem for cell biology. Recent data demonstrating that stereocilia dimensions are controlled by the ionic current through mechanosensitive channels at the tips of stereocilia may help in solving this puzzle. The current chapter describes potential molecular mechanisms of stereocilia bundle formation and maintenance, as well as the mechanisms that optimize the mechanical properties of the hair bundle for effective mechanosensation.

AB - Our sense of hearing is initiated when sound-induced vibrations deflect specialized mechanosensory projections, stereocilia, emanating from the apical surface of the inner ear hair cells. Each hair cell has dozens of stereocilia organized into rows of increasing heights, forming a “hair” bundle. This “staircase” architecture of the stereocilia bundle is common for all vertebrate hair cells and essential for normal mechanosensitivity. Yet, the molecular mechanisms underlying its formation and lifelong maintenance in non-regenerating mammalian auditory hair cells represent a fascinating but yet puzzling problem for cell biology. Recent data demonstrating that stereocilia dimensions are controlled by the ionic current through mechanosensitive channels at the tips of stereocilia may help in solving this puzzle. The current chapter describes potential molecular mechanisms of stereocilia bundle formation and maintenance, as well as the mechanisms that optimize the mechanical properties of the hair bundle for effective mechanosensation.

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Lifelong dynamic maintenance of stereocilia bundles in mammalian auditory hair cells

Abstract

Publication series

Bibliographical note

Funding

Keywords

ASJC Scopus subject areas

Access to Document

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Cite this