神經(jīng)生物學(xué) 學(xué)習(xí)與記憶(英語)

LearningandMemory1.Thebasicconceptsoflearning&memory

classificationoflearning&memorybrainstructureshostinglearning&memorylearning&memoryinbehavioralstudylearning&memoryandneuralplasticity2.Themolecularbasisoflearning&memory

studiesinAplysiastudiesinmouse,LTP,LTDandlongtermmemory2BasicconceptsofLearn&MemLearning：theprocessofacquiringabilityorknowledgethatisnotborn

learned:reading;,writing,drivingetcborn:suckingmilk,yelling,blinkingetcMemory：theretaining/maintainingoflearnedabilityorknowledgeActually,thestudiesonlearningandmemoryincludelearning,repeating,memory,andforgettingaswell3StepsofmemoryprocessingAcquisitionistheprocessofbringingknowledgeintothebrainandintoafirst-stagememorybufferviasensoryorgansandprimarysensorycorticesConsolidationistheprocessofrehearsingandbuildingarobustrepresentationofitinthebrainStorageisthecreationofarelativelystablememorytraceorrecordofknowledgeinthebrainRetrievalistheprocessofreactivatingknowledgeinawaythatwillallowittobecomeanimageinconsciousnessortranslatedintomotoroutput4AmnesiaRetrogradeamnesia:memorylossforeventsbeforethetrauma;youforgetthingsyoualreadyknewAnterogradeamnesia:aninabilitytoformnewmemoriesfollowingbraintrauma.5ClassificationofmemoriesAccordingtotimecourse:WorkingmemoryShorttermmemoryLongtermmemoryAccordingtoappearance:non-declarativememory(implicitmemory)declarativememory(explicitmemory)

6Workingmemory:informationheld“inmind.”Short-termmemory:memoriesthatlastontheorderofsecondstohoursandarevulnerabletodisruption.Long-termmemory:memoriesthatyoucanrecalldays,months,

oryearsaftertheywereoriginallystored.7ImplicitandexplicitmemoryNon-declarativememory(implicitmemory):

Perceptualmemory:acquiredthroughthesense.

Procedurelearning:representationofaseriesofactionsorperceptualprocessingfunctionsthatoccurunconsciouslyandrepetitionstypicallyresultinincreasedspeedoraccuracy

Fearmemory:Declarativememory(explicitmemory):

Episodicmemory:asystemthatcollectstemporarilyandspatiallyencodedeventsinasubject’slife,suchasrecallsofparticularexperiencesorepisodes

Semanticmemory:anorganizationoffactualinformationindependentofspecificepisodesduringwhichthatinformationwasacquired.It’sknowledgeoftheworld.8Declarativeandnon-declarative

memory91.Thebasicconceptsoflearning&memory

classificationoflearning&memory

brainstructureshostinglearning&memorylearning&memoryinbehavioralstudylearning&memoryandneuralplasticity10Brainstructureshostinglearning&memoryGeneraltheoriesaboutmemoryengramLocalizationofdeclarativememory:temporallobediencephalonLocalizationofprocedurememorystriatumLocalizationofworkingmemoryfrontalcortex

11Thesearchforengram-Whereistheengram?Engram-thephysicalrepresentationorlocationofmemory,alsocalledmemorytraceStrategy/Methods:1.lesionorablationofcertainbrainregions2.recordingtheresponseofspecificneurons12EffectofbrainlesionsonMazelearninginrats-KarlLashleyratsgivenbrainlesionsbeforelearningneededmoretrialstorunthemazewithoutgoingdownblindalleysratgivenbrainlesionsafterlearningmademistakesandwentdownblindalleysithadpreviouslylearnedtoavoid.aratrunthroughamazetogetfood13Thegreaterthepercentageofcortexdestroyed,themoreerrorsmadewhiletheratslearntorunthemaze.Thenumberoferrorsshowniscumulativeacrosstrials,suggestingthatratswithlargerlesionshaddifficultyrememberingwhicharmsofthemazewereblindalleys.14KarlLashley’sconclusionsallcorticalareascontributeequallytolearningandmemoryitissimplyamatterofgettingpoorerperformanceonthemazetaskasthelesiongetsbiggerandtheabilitytorememberthemazeworsens.Itiswrongthatallareasareequal,butittruethatthememoriesaredistributed15Brainstructureshostinglearning&memoryGeneraltheoriesaboutmemoryengramLocalizationofdeclarativememory:medialtemporallobediencephalonbrainLocalizationofprocedurememorystriatumLocalizationofworkingmemoryfrontalcortex16LocalizationofdeclarativememoriestoneocortexStudiedinhumanStudiesinmonkeys17ThebrainlesioninpatientH.M.thatproducedsevereanterogradeamnesia.(a)ThemedialtemporallobewasremovedfrombothhemispheresinH.M.’sbraintoalleviatesevereepilepticseizures.(b)Anormalbrain,showingthelocationofthehippocampusandcortexthatwereremovedfromH.M.’sbrain.H.M.haspartialretrogradeamnesiafortheyearsprecedingtheoperation.Muchmoreseriousishisextremeanterogradeamnesia.Whilehecanrememberagreatdealabouthischildhood,heisunabletoremembersomeonehemetjustafewminutesearlier.Casestudy-H.M.18Declarativememoriesinneocortex

-studiesinmonkeysResponsestofacesininferotemporalcortex.(a)ThelocationofareaITintheinferiortemporallobeofamacaquemonkey.(b)Responsesofafacecell.ThehistogramsshowtheresponseofaneuroninareaITtodifferentviewsofamonkey’shead.Thehorizontalbarundereachhistogramindicateswhenthestimuluswaspresented.(c)Changingresponsesofacelltounfamiliarfaces.19DiencephalonandmemoryComponentsofthediencephaloninvolvedinmemory.Thethalamusandmammillarybodiesreceiveafferentsfromstructuresinthemedialtemporallobe.CasestudyofNAandKosakoff’ssyndrome20Casestudy-N.A.Theonlyobviousdamagewasalesioninhisleftdorsomedialthalamus.N.A.’scognitiveabilitywasnormalbuthismemorywasimpaired.Hehadrelativelysevereanterogradeamnesiaandretrogradeamnesiaforaperiodofabout2yearsprecedingtheaccident.Whilehecouldremembersomefacesandeventsfromtheyearsfollowinghisaccident,eventhesememoriesweresketchy.Hehaddifficultywatchingtelevisionbecauseduringcommercials,he’dforgetwhatwaspreviouslyhappening.21Korsakoff’ssyndrome-lesionsinthedorsomedialthalamusandmammillarybodiesNostrongcorrelationexistsbetweentheseverityofanterogradeamnesiaandretrogradeamnesiainKorsakoff’ssyndrome.Themechanismsinvolvedinconsolidation(disruptedinanterogradeamnesia)arelargelydistinctfromprocessesusedtorecallmemories(disruptedinretrogradeamnesia).Anterogradeamnesiamaybeassociatedwithdiencephaliclesionsresultsfromdamagetothethalamusandmammillarybodies.Retrogradeamnesia,mayinvovlesdiencephalon,thecerebellum,brainstem,andneocortex.22Brainstructureshostinglearning&memoryGeneraltheoriesaboutmemoryengramLocalizationofdeclarativememory:Localizationofprocedurememory

striatumLocalizationofworkingmemory

23An

eight-arm

radialarmmaze.Ifaratlearnsthatfouroftheeightarmsnevercontainfood,itwillignoretheseandfollowapathtoonlythebaitedarms.Hippocampusanddeclarativememory24Twoversionsofradialarmmazetask

-declarative/procedurememoryThefirstwasthestandard,inwhichtheratmustmoveasefficientlyaspossibleretrievingthefoodfromeachofthebaitedarmsofthemaze.Inthesecondversion,smalllightswereilluminatedabovethearmscontainingfood,andtheunlitarmshadnofood.ThelightscouldbeturnedonoroffatanytimeThestandardmazetaskwasdesignedtorequiretheuseofdeclarativememory.The“l(fā)ight”versionofthetaskwasintendedtodrawonproceduralmemorybecauseoftheconsistentassociationbetweenthepresenceoffoodandilluminatedlights.25Ifthehippocampalsystemwasdamaged,performancewasdegradedonthestandardmazetaskbutwasrelativelyunaffectedonthelightversion.Conversely,alesioninthestriatumimpairedperformanceofthelighttaskbuthadlittleeffectonthestandardtask.This“doubledissociation”ofthelesionsiteandthebehavioraldeficitsuggeststhatthestriatumispartofaproceduralmemorysystembutisnotcrucialfortheformationofdeclarativememories.26Brainstructureshostinglearning&memoryGeneraltheoriesaboutmemoryengramLocalizationofdeclarativememory:temporallobediencephalonbrainLocalizationofprocedurememorystriatumLocalizationofworkingmemory

frontalcortex,areaLIP

27AreaLIPandworkingmemoryLIP:lateralintraparietalcortex(頂內(nèi)溝外側(cè)區(qū))(a)Themonkeyfixatesonacentralpointwhileaperipheraltargetflashesonandoff.Whenthefixationpointdisappears,andtheanimalknowstomoveitseyestotherememberedlocationofthetarget.(b)ThehistogramshowstheresponseofanLIPneuron.281.Thebasicconceptsoflearning&memory

classificationoflearning&memorybrainstructureshostinglearning&memory

learning&memoryinbehavioralstudylearning&memoryandneuralplasticity2.Themolecularbasisoflearning&memory

studiesinAplysiastudiesinmouse,LTP,LTDandlongtermmemory29Non-associativelearningSensitizationprogressiveamplificationofaresponseafterrepeatedadministrationsofastimulus

GillWithdrawReflexinAplysiaHabituationdecreaseinresponsetoastimulusafterrepeatedpresentationsProbscisextensionresponseinDrosophila“wolf-coming”30Associativelearning

-Classicalconditioning31CS:conditionedstimulus

Asignalingstimulusthatdoesnotelicitaresponsebyitself

US:unconditionedstimulus:

AstimulusisafactorthatcausesaresponseinanorganismConditioning:couplingofCSandUStoelicitaresponse32Associativelearning

-operantcondition