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Active hair bundle movements in auditory hair cells
Author(s) -
Fettiplace Robert
Publication year - 2006
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2006.115949
Subject(s) - prestin , cochlea , basilar membrane , hair cell , bundle , biophysics , mechanotransduction , biology , myosin , stimulus (psychology) , gating , chemistry , inner ear , anatomy , neuroscience , microbiology and biotechnology , materials science , psychology , composite material , psychotherapist
The frequency selectivity of mammalian hearing depends on not only the passive mechanics of the basilar membrane but also an active amplification of the mechanical stimulus by the cochlear hair cells. The common view is that amplification stems from the somatic motility of the outer hair cells (OHCs), changes in their length impelled by voltage‐dependent transitions in the membrane protein prestin. Whether this voltage‐controlled mechanism, whose frequency range may be limited by the membrane time constant, has the band width to cover the entire auditory range of mammals is uncertain. However, there is ample evidence for an alternative mode of force generation by hair cells of non‐mammals, such as frogs and turtles, which probably lack prestin. The latter process involves active motion of the hair bundle underpinned by conformational changes in the mechanotransducer (MT) channels and activation of one or more isoforms of myosin. This review summarizes evidence for active hair bundle motion and its connection to MT channel adaptation. Key factors for the hair bundle motor to play a role in the mammalian cochlea include the size and speed of force production.