title: Active cochlear amplification is dependent on supporting cell gap junctions.
abstract: Mammalian hearing relies upon active cochlear mechanics, which arises from outer hair cell electromotility and hair bundle movement, to amplify acoustic stimulations increasing hearing sensitivity and frequency selectivity. Here we describe the novel finding that gap junctions between cochlear supporting cells also have a critical role in active cochlear amplification in vivo. We find that targeted-deletion of connexin 26 in Deiters cells and outer pillar cells, which constrain outer hair cells standing on the basilar membrane, causes a leftward shift in outer hair cell electromotility towards hyperpolarization, and reduces active cochlear amplification with hearing loss. Coincident with large reduction in distortion product otoacoustic emission and severe hearing loss at high frequencies, the shift is larger in shorter outer hair cells. Our study demonstrates that active cochlear amplification in vivo is dependent on supporting cell gap junctions. These new findings also show that connexin 26 deficiency can reduce active cochlear amplification to induce hearing loss.
authors: Department of Otolaryngology, University of Kentucky Medical School, Lexington, Kentucky 40536, USA.
authors: Yan
authors: Y
authors: Zhu
authors: Chun
authors: C
authors: Liang
authors: Jin
authors: J
authors: Chen
authors: Liang
authors: L
authors: Zong
authors: Guang-Di
authors: GD
authors: Chen
authors: Hong-Bo
authors: HB
authors: Zhao
mesh_terms: D000818:Animals; D001309:Auditory Threshold; D003055:Cochlear Microphonic Potentials; D000072259:Connexin 26; D017630:Connexins / Q000172:deficiency / Q000378:metabolism; D016057:Evoked Potentials, Auditory, Brain Stem; D017629:Gap Junctions / Q000378:metabolism*; D017353:Gene Deletion; D018390:Gene Targeting; D018072:Hair Cells, Auditory, Outer / Q000473:pathology; D034381:Hearing Loss / Q000473:pathology / Q000503:physiopathology; D007760:Labyrinth Supporting Cells / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D020409:Molecular Motor Proteins / Q000378:metabolism; D017711:Nonlinear Dynamics; D017084:Otoacoustic Emissions, Spontaneous; D013136:Spiral Ganglion / Q000473:pathology / Q000503:physiopathology
chemical_list: D017630:Connexins; C000607043:Gjb2 protein, mouse; D020409:Molecular Motor Proteins; C498720:Pres protein, mouse; D000072259:Connexin 26
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