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.