简介：Cisplatindamagescochlearhaircellsandspiralganglionneuronsthroughcelldeathsignalingpathwaysthatarenotfullyunderstood.Weusedfocusedapoptosisgenemicroarraystostudyearlychangesingeneexpres-sionincochlearculturesfromP3neonatalratstreatedwithcisplatin(0.2mM).After12hoursofcisplatintreat-ment,morethan50%ofthe96genesonthearrayshowedasignificantdecreaseinexpression,consistentwithwidespreadcelldeath.However,after3hoursofcisplatintreatment,10genesshowedsignificantincreaseinex-pressionintotalcochleartissue.Inexperimentswithsubsetsofcochleartissues,at3h,cisplatininducedincreasedexpressionof12genesinthecochlearsensoryepithelium(basilarmembrane)and11genesinthespiralganglion(tissueofRosenthal'scanal,containingthespiralganglion).Theseincludedpro-andanti-apoptoticgenesin-volvedinthep53signalingpathway,TNFreceptorfamily,NF-kappaBpathway,deathdomainfamily,deatheffec-tordomainfamily,Bcl-2family,CARDfamily,TRAFfamily,andGTPsignaltransduction.Althoughthechangesingeneexpressionshowedanoverlapbetweenbasilarmembraneandspiralganglion,otherchanges,whichmayreflecttheuniqueresponseofeachtissue,werealsoobserved.Pifithrin-αblockedcisplatin-inducedup-regulationofgenesinthep53signalingpathwaywhenassayedbybothsuperarrayandrealtimePCR.Thedataaddtoourunderstandingoftheinvolvementofp53incisplatin-inducedototoxicityandotoprotection,conferredbythep53inhibitorPifithrin-α.

简介：Thedevelopmentandplasticityofcentralauditorysystemcanbeinfluencedbythechangeofperipheralneuronalactivity.However,themolecularmechanismparticipatingintheprocessremainselusive.Brain-derivedneurotrophicfactor(BDNF)bindingwithitsfunctionalreceptortropomyosinreceptorkinaseB(TrkB)hasmultipleeffectsonneurons.Hereweusedaratmodelofauditorydeprivationbybilateralcochlearablation,toinvestigatethechangesinexpressionofBDNFandTrkBintheauditorycortexafterauditorydeprivationthatoccurredduringthecriticalperiodforthedevelopmentofcentralauditorysystem.Reversetranscription-quantitativepolymerasechainreaction(RTqPCR)andimmunohistochemistrymethodswereadoptedtodetectthemRNAandproteinexpressionlevelsofBDNFandTrkBintheauditorycortexat2,4,6and8weeksaftersurgery,respectively.ThechangeintheexpressionofBDNFandTrkBmRNAsandproteinsfollowedsimilartrend.Inthebilateralcochlearablationgroups,theBDNF-TrkBexpressionlevelinitiallydecreasedat2weeksbutincreasedat4weeksfollowedbythereductionat6and8weeksaftercochlearremoval,ascomparedtotheage-matchedshamcontrolgroups.Inconclusion,theBDNF-TrkBsignalingisinvolvedintheplasticityofauditorycortexinanactivity-dependentmanner.