Thermal Excitation of the Mechanotransduction Apparatus of Hair Cells.

Publication Type Academic Article
Authors Azimzadeh J, Fabella B, Kastan N, Hudspeth A
Journal Neuron
Volume 97
Issue 3
Pagination 586-595.e4
Date Published 02/07/2018
ISSN 1097-4199
Keywords Hair Cells, Auditory, Mechanotransduction, Cellular, Ultraviolet Rays
Abstract Although a hair bundle is normally deflected by mechanical stimuli, we found that irradiation of a hair cell from the bullfrog's sacculus with ultraviolet light causes rapid motion of the hair bundle toward its tall edge. This movement is associated with opening of mechanotransduction channels and disappears when tip links are disrupted. We localized the absorptive element responsible for the motion to the region directly below the hair bundle and measured an action spectrum similar to the absorption spectra of mitochondrial constituents. Temperature measurements revealed heating around the site of absorption; direct heating of the hair bundle confirmed that the response to light is mediated through heat. Although mechanical offsets of the hair bundle revealed that heat softens gating springs, it also acts directly to open transduction channels. This study identifies an unconventional method of hair-cell stimulation and clarifies the previously unexplained sensitivity of auditory organs to thermal stimulation.
DOI 10.1016/j.neuron.2018.01.013
PubMed ID 29395911
PubMed Central ID PMC5805653
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