简介:ObjectiveToinvestigatetheearlychangeofcochlearribbonsynapsesoninnerhaircellsinresponsetoaminoglycosideototoxicity.MethodsC57BL/6Jmicereceivedintraperitonealinjectionofgentamicin(100mg/kg/day),andtheapicalcoilorganofCortiwasexaminedonthe4th,7thand10thday(n=10).Litter-mateswithoutgentamicintreatmentservedascontrols(n=10).RIBEYEonthepresynapticmembraneandAMPAreceptorsonthepostsynapticmembranewerelabeledwithCtBP2orGluR2/3respectively.Threedi-mensionreconstructionwasconductedusingthe3DSMAX8.0software.ResultsTherewerenodisruptionsofouterorinnerhaircellsinallgroups.However,thenumberofribbonsynapsesoncochlearinnerhaircellsincreasedsignificantlywithin7daysaftergentamicinexposure(P<0.01),followedbyasignificantde-creaseafter7days.ConclusionDuringtheearlystageofaminoglycosideototoxicity,increasedpopulationofcochlearribbonsynapsesmayindicateasignificantdown-regulationofsynapticfunction.
简介:ObjectiveTostudycharacteristicsofhearinglossafterexposuretomoderatenoiseexposureinC57BL/6Jmice.MethodsMaleC57BL/6Jmicewithnormalhearingatageof5-6weekswerechosenforthisstudy.Themicewererandomlyselectedtobestudiedimmediatelyafterexposure(GroupP0),or1day(GroupP1),3days(GroupP3),7days(GroupP7)or14days(P14)afterexposure.Theirbeforeexposureconditionservedasthenormalcontrol.Allmicewereexposedtoabroad-bandwhitenoiseat100dBSPLfor2hours,ABRthresholdswereusedtoestimatehearingstatusateachtimepoint.ResultsABRthresholdelevationwasseenateverytestedfrequencyatP0(P<0.01).Elevationathigh-frequencies(16kHzand32kHz)wasgreaterthanatlowerfrequencies(4kHzand8kHz,P<0.05).FromP1toP14,ABRthresholdscontinuouslyimproved,andtherewasnosignificantdifferencebetweenP14andbeforeexposure(P>0.05).ConclusionThereisafrequencyspecificresponseto100dBSPLbroad-bandwhitenoiseinC57BL/6Jmice,withthehigh-frequencybeingmoresusceptible.HearinglossinducedbymoderatenoiseexposureappearsreversibleinC57BL/6Jmice.
简介:目的:本研究探讨学语初期听障儿童的听觉年龄与接受听觉口语法治疗的时间对语言发展的影响。方法选取台湾雅文儿童听语文教基金会听障个案18名,听觉年龄为8~16个月,以华语婴幼儿沟通发展量表婴儿版测验其语言能力,与相同听觉年龄的健听儿童常模成绩进行比较,预测分析听觉年龄和听觉口语法治疗时间对语言测验成绩的影响。结果听障儿童词汇理解与相同听觉年龄的健听儿童没有差异(P〉0.05),但词汇表达显著落后于相同听觉年龄健听儿童。听障儿童早期及晚期手势沟通能力比相同听觉年龄健听儿童表现优异。此外,听障儿童的听觉年龄及康复时间亦能有效预测其词汇理解及晚期手势沟通的表现。结论学语初期听障儿童接受与健听儿童相同时间的听觉和语言刺激,其词汇理解发展速度与健听儿童无差异。听障儿童早期及晚期手势沟通能力皆优于健听儿童,且词汇理解和晚期手势沟通的表现随听觉口语法治疗时间的增加而上升,表明听觉口语法治疗在听障儿童学语初期的效果首先反映在词汇理解和晚期沟通手势上。