简介：Toinvestigatetheglutamate-likeimmunoreactivity(Glu-IR)changesininnerhaircells(IHCs)ofguineapigscochlearafternoiseexposure.Guineapigsweredistributedinto6groupsincludingcontrolgroup(gl),andgroupsofimmediately(g2),8hours(g3),1day(g4),3days(g5)and7days(g6)afternoiseexposure.Theexperimentalgroupswereexposedto120dBLp1/3octave4kHznarrowbandnoisefor4hourstoruintheorganofCorti.ThefirstturnoftheorganofCortiwasdissectedtomakeultrathinsectionsandunderwentimmunoelectronstudy.ThedensityofgoldparticlesofGlu-IRinIHCswasmeasured.ResultsshowedthatGlu-IRinIHCsafternoiseexposurechangeddynamically.ThedensityofgoldparticleinIHCsofg2significantlyincreased(p<0.001)comparedwithglanddecreaseding3(p<0.001),whereastherewerenosignificantdifferenceinthegroupsofg4,g5andg6(p>0.05).TheresultssuggestthattheremaybeglutamateautoreceptorsinthemembraneofIHCsandtheglutamatereleasedfrompre-synapsemayactontheseautoreceptorsinapostitivefeedbackmanner,whichinduced[Ca^2+]increasedinIHCsimmediatelyafternoiseexposure.GlutamatesynthetasesystemwasactivatedbyCa^2+andmoreglutamicacidwasproduced.Inthegroupof8hoursafternoiseexposure,glutamicaciddecreasedinIHCsbecauseofitsover-releasingintosynapses.Glu-IR'srecoverytonormallevelindicatedthattheglutamateglutaminecyclemayexistinguineapigcochlea.

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