Dynamic changes in hair cell ribbon synapse induced by loss of spiral ganglion neurons in mice

作     者：Yuan Yasheng Chi Fanglu 

作者机构：Department of Otolaryngology Eye Ear Nose & Throat HospitalFudan University Shanghai 200031 China Department of Otolaryngology MEEI Harvard Medical SchoolBoston MA 02115 USA (Yuan YS) 

出 版 物：《Chinese Medical Journal》 (中华医学杂志（英文版）)

年 卷 期：2014年第127卷第10期

页      面：1941-1946页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 071006[理学-神经生物学] 

基　　金：This study was supported by grants from the NSFC Grant (No.81028003/H1305 and No.30973303) the Ministry of Education Grant (No.20090071120072) the Key Basic Research Project of Shanghai Committee of Science and Technology (No.10JC1402500)and the Innovation Program of Shanghai Committee of Science and Technology (No.11411952300) 

主　　题：auditory neurons hair cells ribbon synapse degeneration 

摘      要：Background Previous studies have suggested that primary degeneration of hair cells causes secondary degeneration of spiral ganglion neurons （SGNs）,but the effect of SGN degeneration on hair cells has not been *** the adult mouse inner ear ouabain can selectively and permanently induce the degeneration of type 1 SGNs while leaving type 2 SGNs,efferent fibers,and sensory hair cells relatively *** study aimed to investigate the dynamic changes in hair cell ribbon synapse induced by loss of SGNs using ouabain application to the round window niche of adult *** In the analysis,24 CBA/CAJ mice aged 8-10 weeks,were used,of which 6 normal mice were used as the control *** ouabain application in the round window niche 6 times in an hour,ABR threshold shifts at least 30 dB in the three experimental groups which had six mice for 1-week group,six for 1-month group,and six for 3-month *** 24 animals underwent function test at 1 week and then immunostaining at 1 week,1 month,and 3 *** The loss of neurons was followed by degeneration of postsynaptic specializations at the afferent synapse with hair *** week after ouabain treatment,the nerve endings of type 1 SGNs and postsynaptic densities,as measured by Na/K ATPase and PSD-95,were affected but not entirely missing,but their partial loss had consequences for synaptic ribbons that form the presynaptic specialization at the synapse between hair cells and primary afferent *** numbers in inner hair cells decreased （some of them broken and the ribbon number much decreased）,and the arrangement of the synaptic ribbons had undergone a dynamic reorganization：ribbons with or without associated postsynaptic densities moved from their normal location in the basal membrane of the cell to a more apical location and the neural endings alone were also found at more apical locations without associated *** 1 month,when the neural postsynaptic densities had completed their de