Prestin derived OHC surface area reduction underlies age-related rescaling of frequency place coding

Yu Zhang; Guotong Lin; Yi Wang; Na Xue; Xin Lin; Tingting Du; Wei Xiong; Lei Song

doi:10.1016/j.heares.2021.108406

Prestin derived OHC surface area reduction underlies age-related rescaling of frequency place coding

Hear Res. 2022 Sep 15:423:108406. doi: 10.1016/j.heares.2021.108406. Epub 2021 Nov 27.

Authors

Yu Zhang¹, Guotong Lin¹, Yi Wang², Na Xue¹, Xin Lin³, Tingting Du⁴, Wei Xiong⁵, Lei Song⁶

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
² School of Life Sciences, Tsinghua University, Beijing, China; IDG/McGovern Institute for Brain Research at Tsinghua University, Tsinghua University, Beijing, China. Electronic address: yiwang2020@mail.tsinghua.edu.cn.
³ Department of Otolaryngology-Head and Neck Surgery, Shanghai Zhongshang Hospital, Fudan University School of Medicine, Shanghai, China.
⁴ Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China. Electronic address: tingtingdu@sh-jei.org.
⁵ School of Life Sciences, Tsinghua University, Beijing, China; IDG/McGovern Institute for Brain Research at Tsinghua University, Tsinghua University, Beijing, China. Electronic address: wei_xiong@tsinghua.edu.cn.
⁶ Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China. Electronic address: lei.song@yale.edu.

PMID: 34933788
DOI: 10.1016/j.heares.2021.108406

Abstract

Outer hair cells (OHC) are key to the mammalian cochlear amplifier, powered by the lateral membrane protein Prestin. In this study, we explored age-related OHC changes and how the changes affected hearing in mouse. OHC nonlinear membrane capacitance measurements revealed that, starting upon completion of postnatal auditory development, a continuous reduction of total Prestin in OHCs accompanied by a significant reduction in their cell surface area. Prestin's density is unaffected by Prestin level drop over the whole age range tested, suggesting that the OHC size reduction is Prestin-dependent. Stereocilia length in aged OHCs remained unchanged but the first row stereocilia on the aged inner hair cells (IHCs) were elongated. Distortion product otoacoustic emission (DPOAE) group delays became longer with aging, suggesting an apical shift in vibration on basilar membrane. Acoustic lesion experiments revealed an apical shift in damage place in old cochleae accompanied by a shallower progression in synaptic damage over a wider frequency range that was indicative of a broader frequency filter. Overall, these findings suggest that in aging cochlea, a shift in frequency place coding could occur due to the changes in cochlear active and passive mechanics. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.

Keywords: Aging; Cochlear mechanics; DPOAE group delay; Frequency coding; Outer hair cell; Prestin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cochlea / metabolism
Hair Cells, Auditory, Outer* / metabolism
Hair Cells, Vestibular*
Hearing
Mammals
Mice
Otoacoustic Emissions, Spontaneous