An Introduction to
Auditory
Mechanosensing
Presented by Jared Ilan
Ear Anatomy
Sarah H. Hayes, Dalian Ding, Richard J. Salvi, Brian L. Allman. Chapter 1 - Anatomy and physiology of
the external, middle and inner ear. Editor(s): Gastone G. Celesia. Handbook of Clinical Neurophysiology,
Elsevier, Volume 10, 2013, Pages 3-23. ISSN 1567-4231. ISBN 9780702053108.
https://doi.org/10.1016/B978-0-7020-5310-8.00001-6.
(https://www.sciencedirect.com/science/article/pii/B9780702053108000016)
External Ear:
Middle Ear:
External Ear (Cochlea):
Flange → Concha →
Meatus
Sealed by tympanic
membrane (ear drum)
Stapes vibration transmits to
perilymph in scala vestibuli
Pressure increase
(frequency dependent)
Vibrations transmitted
through ossicles, helps
overcome fluid impedance
Wave passes through basilar
membrane to scala media;
sensing at organ of Corti
Resonance in ear canal
Muscles pull on ossicular
chain with intense LF sound
Pressure relief at scala
tympani (round window)
Organ of Corti & Hair Cells
Organ of Corti
Located within scala media, on basilar
membrane along cochlear tube
One row of inner hair cells (IHCs) and three rows
of outer hair cells (OHCs)
Tectorial membrane- Gelatinous structure
coupled to OHCs
Hair Cells
Amplify (OHC) and sense (IHC) sound waves
Stereocilia: Height-ordered microvilli rich in
actin, protrude from apical surface
Deflection of stereocilia activates
mechanotransduction pathway
Giusy A. Caprara, Anthony W. Peng. Mechanotransduction in mammalian sensory hair cells. Molecular
and Cellular Neuroscience, Volume 120, 2022, 103706
ISSN 1044-7431. https://doi.org 10.1016/j.mcn.2022.103706.
(https://www.sciencedirect.com/science/article/pii/S1044743122000124)
Hair Cell Mechanosensing
Giusy A. Caprara, Anthony W. Peng. Mechanotransduction in mammalian sensory hair cells. Molecular
and Cellular Neuroscience, Volume 120, 2022, 103706
ISSN 1044-7431. https://doi.org 10.1016/j.mcn.2022.103706.
(https://www.sciencedirect.com/science/article/pii/S1044743122000124)
Tip links
Connect stereocilia within hair bundle
Composed of Cadherin 23 (CDH23)
and protocadherin 15 (PCDH15)
Pulling of tip link towards tallest
stereocilia opens ion channel
(magnitude-dependent)