检索结果-南通市图书馆

The role of Rho GTPase family in cochlear hair cells and hearing

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第10期18卷 2167-2172页

作者： Yu-Bei Dai Xiang Gao Dong Liu Jie Gong School of Life Science Nantong Laboratory of Development and DiseasesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of EducationCo-innovation Center of NeuroregenerationNantong UniversityNantongJiangsu ProvinceChina

Rho GTPases are essential regulators of the actin cytoskeleton.They are involved in various physiological and biochemical processes such as the regulation of cytoskeleton dynamics,development,proliferation,survival,and regeneration.During the development of cochlear hair cells,Rho GTPases are activated by various extracellular signals through membrane receptors to further stimulate multiple downstream effectors.Specifically,RhoA,Cdc42,and Rac1,members of the classical subfamily of the Rho GTPase family,regulate the development and maintenance of cilia by inducing the polymerization of actin monomers and stabilizing actin filaments.In addition,they also regulate the normal morphology orientation of ciliary bundles in auditory hair cells,which is an important element of cell polarity regulation.Moreover,the actin-related pathways mediated by RhoA,Cdc42,and Rac1 also play a role in the motility of outer hair cells,indicating that the function of Rho GTPases is crucial in the highly polar auditory sensory system.In this review,we focus on the expression of RhoA,Cdc42,and Rac1 in cochlear hair cells and how these small molecules participate in ciliary bundle morphogenesis and cochlear hair cell movement.We also discuss the progress of current research investigating the use of these small molecules as drug targets for deafness treatment.

关键词： actin assembly auditory sensory neurons cell polarity cell proliferation electromotility hair cell hearing loss morphogenesis Rho GTPases stereocilia

Prestin-Mediated Frequency Selectivity Does not Cover Ultrahigh Frequencies in Mice

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2022年第7期38卷 769-784页

作者： Jie Li Shuang Liu Chenmeng Song Tong Zhu Zhikai Zhao Wenzhi Sun Yi Wang Lei Song Wei Xiong School of Life Sciences Tsinghua UniversityBeijing 100084China IDG/MeGovern Institute for Brain Research at Tsinghua University Tsinghua UniversityBeijing 100084China Chinese Institute for Brain Research Beijing 102206China School of Basic Medical Sciences Capital Medical UniversityBeijing 100069China Department of Otolaryngology Head and Neck SurgeryShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China Ear Institute Shanghai Jiao Tong University School of MedicineShanghai 200092China Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases Shanghai 20001lChina

In mammals,the piezoelectric protein,Prestin,endows the outer hair cells(OHCs)with electromotility(eM),which confers the capacity to change cellular length in response to alterations in membrane potential.Together with basilarmembrane resonance and possible stereociliary motility,Prestin-based OHC eM lays the foundation for enhancing cochlear sensitivity and frequency selectivity.However,it remains debatable whether Prestin contributes to ultrahigh-frequency hearing due to the intrinsic nature of the cel's low-pass features.The low-pass_property of mouse OHC eM is based on the finding that eM magnitude dissipates within the frequency bandwidth of human speech.In this study,we examined the role of Prestin in sensing broad-range frequencies(4-80 kHz)in mice that use ultrasonic hearing and vocalization(to>100 kHz)for social communication.The audiometric measurements in mice showed that ablation of Prestin did not abolish hearing at frequencies>40 kHz.Acoustic associative behavior tests confirmed that Prestin-knockout mice can learn ultrahigh-frequency sound-coupled tasks,similar to control mice.Ex vivo cochlear Ca2+imaging experiments demonstrated that without Prestin,the OHCs still exhibit ultrahigh-frequency transduction,which in contrast,can be abolished by a universal cation channel blocker,Gadolinium.In vivo salicylate treatment disrupts hearing at frequencies40 kHz.These findings demonstrate that cochlear OHCs are the target cells that support ultrahigh-frequency transduction,which does not require Prestin.

关键词： Prestin PIEZO2 Ultrahigh-frequency hearing electromotility Outer hair cells

Prestin forms tetramer with each subunit being mechanically independent

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Otology 2009年第2期4卷 86-97页

作者： WANG Xiang 1, GUO Wei-wei 2, HE David Zhi-Zhou1, YANG Shi-Ming 2 1 Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA 2 Institute of Otolaryngology, Department of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Beijing 100853 Department of Biomedical Sciences Creighton University School of Medicine Omaha NE 68178 USA Institute of Otolaryngology Department of Otolaryngology Head and Neck Surgery Chinese PLA General Hospital Beijing 100853

Prestin is the motor protein of cochlear outer hair cells （OHCs）. It is able to perform rapid and reciprocal electromechanical conversion that underlies OHC electromotility. Due to the inadequate size of a single prestin molecule to form the2 nm intramembraneous protein particles （IMPs） in the OHC lateral membrane （LM）, the possibility of prestin oligomerization has been proposed. It has been suggested that prestin molecules form highorder oligomers, most likely as the tetramer, in heterologous systems. In OHCs, however, the oligomeric structure of prestin remains unclear. Here we calculated the prestin-related charge density in both gerbil and guinea pig OHCs through measuring their nonlinear capacitance （NLC） and LM surface area, showing that the average charge density （22, 608 μm-2 in gerbils; 19, 460 μm-2 in guinea pigs） is statistically 4 times the average density of IMPs （5,686 μm-2 in gerbils; 5, 000 μm-2 in guinea pigs）. This suggests that each IMP contains four prestin molecules based upon the notion that each prestin transfers a single elementary charge, implying that prestin forms tetramers in OHCs. To determine whether the prestin tetramer functions as a mechanical unit, we subsequently compared the slope factors （α） of electromotility and NLC simultaneously measured from the same OHC, showing that the α values of the two are statistically the same. This suggests that each prestin molecule in the tetramer is mechanically independent and equally contributes to OHC electromotility.

关键词： Prestin oligomer outer hair cells electromotility nonlinear capacitance gerbil

An Overview of Electrically Evoked Otoacoustic Emissions in the Mammalian Cochlea

在线全文

学校读者我要写书评

暂无评论

Journal of Otology 2006年第1期1卷 45-50页

作者： Alfred L. Nuttall Oregon Hearing Research Center Department of Otolaryngology/Head & Neck SurgeryOregon Health & Science University 3181 SW Sam Jackson Park RoadNRC04 Portland Oregon 97239 USA Kresge Hearing Research Institute The University of Michigan 1301 EastAnn Street Ann Arbor Michigan 48109-0506 USA Biomedical Engineering Oregon Health & Science University 20000 NWWalker Road Beaverton OR 97006 USA Shanghai Jiao Tong University Shanghai P.R.China

Alternating currents injected into the cochlea are able to evoke outer hair cell-mediated basilar membrane motion, thus give rise to production of otoacoustic emissions. This electrically evoked otoacoustic emission(EEOAE) provides a useful tool for the research of out hair cell electromotility in vivo. This article reviews the research work on EEOAEs in mammals. Features of the EEOAEs and theories of their generation are introduced. Methods of EEOAE measurement are also described.

关键词： cochlea out hair cell electromotility otoacoustic emissions electrical stimulation

Functional maturation of outer hair cells in the rat cochlea

在线全文

学校读者我要写书评

暂无评论

Functional maturation of outer hair cells in the rat cochlea

Direct current pulse elicits basilar membrane vibration in guinea pigs

中国神经科学学会第十届全国学术会议

作者： Ming-Yu FU Zhong-Ju XIAO Jie TANG Department of Physiology School of Basic Medical SciencesSouthern Medical University

Mammalian cochlear outer hair cells（OHCs） have the unique capability of rapidly changing their length in response to membrane voltage change.Termed electromotihty,such shape changes are responsible for cochlear amplification,which contributes to the exquisite frequency selectivity and sensitivity observed in the mature mammalian cochlear.It is well known that the first sign of auditory function in rat central neural system occurs at 11days after birth.However,the precise timing of OHC electromotihty has not been defined.In the present study,OHCs isolated from the cochleae of postnatal rats,ranging in age from 0 to 19 days,were examined with immuncytochemical and electrophysiological methods.A stepwise increasing in cell length of OHCs was observed from 0 day after birth（DAB） until 12 DAB.Prestin,a unique voltage-dependent motor protein found in the membrane of mammalian OHCs,confers OHCs with electromotility.The first membrane expression of Prestin appeared at 4 DAB.Non-hnear capacitance（NLC） and somatic motibty,two hallmarks representing prestin function,were measured from OHCs.The NLC magnitude increased over several days until 14 DAB,and correlated with prestin immunoreactivity.Since the onset of hearing and frequency fine tuning development in rats occurs between 11 and 14 DAB,our results suggest that the onset of OHC electromotihty occurs earlier than that of auditory function and the maturation of the motibty amplitude correlated with the development of fine tuning.

关键词： auditory system outer hair cell electromotility development prestin

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Medical Colleges of PLA(China) 2000年第3期15卷 231-235页

作者：郭梦和任田英 Alfred L Nuttall

Objective:To study the electromotility of the basilar membrane (BM) of guinea pigs in vivo. Methods :A pair of platinum-iridium wire electrodes were deposited into the holes drilled into the scala vestibuli and scala tympani on the basal turn of cochlea. The organ of Corti was stimulated with rectangular, constant current pulses . The displacement and velocity of BM were measured with laser doppler velocimeter. Results: The electrically elicited displacement of BM moved toward the scala where the electrode was positively charged. The waveform of BM displacement generally corresponded to the shape of the rectangular pulse of electric current. Ringing responses could be seen at the onset and offset of current pulse reflecting transient responses of the organ of Corti. In the cochlea of hearing-impaired or dead animal, direct current (DC) could still elicit a BM displacement but the ringing response was attenuated or disappeared. This phenomenon was probably due to metabolic disturbance in the damaged outer hair cells. In the sensitive cochlea, the BM vibration induced with direct current was similar to that induced by acoustic stimulation, and the BM moves in a traveling wave pattern. Conclusion: The findings of this experiment implicated that the DC stimulation of the cochlea conduces the contraction or elongation of OHCs. The electromotility of OHCs provides sufficient force to displace the BM. In the electrically stimulated normal cochlea,transient response of OHCs can induce resonant vibration at the same frequency as that Of the characteristic frequency (CF) of a partition in the BM. The vibration should be an active process of energy depletion associated with the cochlear amplifier.The vibration of BM can propagate to other partition of BM according to the traveling wave theory. This characteristic has laid the foundation for the electromotile hearing and electrically evoked otoacoustic emission.

关键词： cochlea vibration basilar membrane electromotility