scholarly journals Fluid Jet Stimulation of Auditory Hair Bundles Reveal Spatial Non-uniformities and Two Viscoelastic-Like Mechanisms

2021 ◽  
Vol 9 ◽  
Author(s):  
Anthony W. Peng ◽  
Alexandra L. Scharr ◽  
Giusy A. Caprara ◽  
Dailey Nettles ◽  
Charles R. Steele ◽  
...  
Keyword(s):  
Hair Cell ◽  
High Speed ◽  
Outer Hair Cell ◽  
Hair Bundle ◽  
Small Contribution ◽  
Passive System ◽  
High Speed Imaging ◽  
Exponential Process ◽  
Double Exponential ◽  
Stimulation Of

Hair cell mechanosensitivity resides in the sensory hair bundle, an apical protrusion of actin-filled stereocilia arranged in a staircase pattern. Hair bundle deflection activates mechano-electric transduction (MET) ion channels located near the tops of the shorter rows of stereocilia. The elicited macroscopic current is shaped by the hair bundle motion so that the mode of stimulation greatly influences the cell’s output. We present data quantifying the displacement of the whole outer hair cell bundle using high-speed imaging when stimulated with a fluid jet. We find a spatially non-uniform stimulation that results in splaying, where the hair bundle expands apart. Based on modeling, the splaying is predominantly due to fluid dynamics with a small contribution from hair bundle architecture. Additionally, in response to stimulation, the hair bundle exhibited a rapid motion followed by a slower motion in the same direction (creep) that is described by a double exponential process. The creep is consistent with originating from a linear passive system that can be modeled using two viscoelastic processes. These viscoelastic mechanisms are integral to describing the mechanics of the mammalian hair bundle.

scholarly journals In situ motions of individual inner-hair-cell stereocilia from stapes stimulation in adult mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yanli Wang ◽  
Charles R. Steele ◽  
Sunil Puria ◽  
Anthony J. Ricci
Keyword(s):  
Hair Cell ◽  
High Speed ◽  
Ex Vivo ◽  
Ionic Currents ◽  
Hair Bundle ◽  
Sensory Cells ◽  
Apical Surface ◽  
Inner Hair Cell ◽  
High Speed Imaging

AbstractIn vertebrate hearing organs, mechanical vibrations are converted to ionic currents through mechanoelectrical-transduction (MET) channels. Concerted stereocilia motion produces an ensemble MET current driving the hair-cell receptor potential. Mammalian cochleae are unique in that the tuning of sensory cells is determined by their mechanical environment and the mode of hair-bundle stimulation that their environment creates. However, little is known about the in situ intra-hair-bundle motions of stereocilia relative to one another, or to their environment. In this study, high-speed imaging allowed the stereocilium and cell-body motions of inner hair cells to be monitored in an ex vivo organ of Corti (OoC) mouse preparation. We have found that the OoC rotates about the base of the inner pillar cell, the hair bundle rotates about its base and lags behind the motion of the apical surface of the cell, and the individual stereocilia move semi-independently within a given hair bundle.

Active Hair Bundle Movements and the Cochlear Amplifier

2003 ◽  
Vol 14 (06) ◽  
pp. 325-338 ◽  
Author(s):  
Anthony Ricci
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Sensorineural Hearing Loss ◽  
Outer Hair Cell ◽  
Sensorineural Hearing ◽  
Hair Bundle ◽  
Cochlear Amplifier ◽  
Active Process ◽  
Slow Adaptation ◽  
Active Processes

The “active process” is a term used to describe amplification and filtering processes that are essential for obtaining the exquisite sensitivity of hearing organs. Understanding the components of the active process is important both for our understanding of the normal physiology of hearing and because perturbations of the cochlear amplifier may lead to such maladies as threshold shifts (both temporary and permanent), tinnitus, sensorineural hearing loss and presbicusis. To date the cochlear amplifier has largely been attributed to outer hair cell electro motility; however, recent evidence suggests, that active properties of the hair bundle may also be important. Most likely both somatic motility and active hair bundle movements contribute to establishing the cochlear active process. This paper reviews recent evidence regarding known active processes in the hair bundle gating compliance, and fast and slow adaptation.

Outer hair cell somatic, not hair bundle, motility is the basis of the cochlear amplifier

2008 ◽  
Vol 11 (7) ◽  
pp. 746-748 ◽  
Author(s):  
Marcia M Mellado Lagarde ◽  
Markus Drexl ◽  
Victoria A Lukashkina ◽  
Andrei N Lukashkin ◽  
Ian J Russell
Keyword(s):  
Hair Cell ◽  
Outer Hair Cell ◽  
Hair Bundle ◽  
Cochlear Amplifier

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

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