神經(jīng)生物學(xué)第九章 運(yùn)動(dòng)和運(yùn)動(dòng)疾病

運(yùn)動(dòng)和運(yùn)動(dòng)疾病

MovementandMovementDisordersMotorSystem

運(yùn)動(dòng)系統(tǒng)軀體運(yùn)動(dòng)系統(tǒng)（Somaticmotorsystem自主運(yùn)動(dòng)系統(tǒng)（autonomicnervoussystem/Visceralmotorsystem）2MotorSystem

運(yùn)動(dòng)系統(tǒng)軀體運(yùn)動(dòng)系統(tǒng)（Somaticmotorsystem）：中樞神經(jīng)系統(tǒng)中與運(yùn)動(dòng)控制有關(guān)結(jié)構(gòu)的總稱，包括大腦皮層、腦干、脊髓、基地神經(jīng)節(jié)、小腦和外周軀體運(yùn)動(dòng)神經(jīng)纖維。其作用是生成運(yùn)動(dòng)計(jì)劃（plan）、編制運(yùn)動(dòng)程序（program），并向骨骼肌發(fā)出運(yùn)動(dòng)指令（command）,以引起骨骼肌的收縮活動(dòng)而產(chǎn)生軀體運(yùn)動(dòng)。3SomaticMotorSystem

（軀體運(yùn)動(dòng)系統(tǒng)）

Threetypesofmovement（三種類型的運(yùn)動(dòng)）Theorganizationofmovement（運(yùn)動(dòng)的等級(jí)組織）Neuralstructuresinvolvedincontrollingmovements（控制運(yùn)動(dòng)的神經(jīng)結(jié)構(gòu)）

4TypesofMovements

（運(yùn)動(dòng)類型）反射運(yùn)動(dòng)Reflexivemovements：最簡(jiǎn)單和最基本的運(yùn)動(dòng)方式，很少受意識(shí)的影響，具有等級(jí)反應(yīng)性的特征（反應(yīng)的幅度和速度與刺激強(qiáng)度有關(guān)）隨意運(yùn)動(dòng)Voluntarymovements：為了達(dá)到某種目的而指向一定目標(biāo)的運(yùn)動(dòng)。節(jié)律性運(yùn)動(dòng)Rhythmicmovements：介于反射運(yùn)動(dòng)和隨意運(yùn)動(dòng)間的一類運(yùn)動(dòng)。比如呼吸、心跳等。5TheOrganizationofMovement

（運(yùn)動(dòng)的等級(jí)組織）SpinalmotorneuronsexecutemovementThebrainstemmodulatestheactionofspinalmotorcircuitsThecerebralcortexmodulatestheactionofmotorneuronsinthebrainstemandspinalcord6NeuralStructuresInvolvedinControllingMovementSpinalcord脊髓Brainstem腦干Cerebralmotorcortex

運(yùn)動(dòng)皮層Controlmovements7NeuralStructuresInvolvedinControllingMovementSpinalcordBrainstemCerebralmotorcortexCerebellum小腦Basalganglion基底神經(jīng)節(jié)Controlmovementsmodulation8SpinalControlofMovement

運(yùn)動(dòng)的脊髓調(diào)控9LowerMotorNeurons

（低位運(yùn)動(dòng)神經(jīng)元）

Lowermotorneuron:inventralhornofspinalcordAlphamotorneurons（α運(yùn)動(dòng)神經(jīng)元）:Predominantlyinspinalcord–axonssynapseonskeletalmusclesGammamotorneurons（γ運(yùn)動(dòng)神經(jīng)元）:Locatedamongalphamotorneuronsandinnervateintrafusalfibers（梭內(nèi)肌纖維）ofskeletalmusclesExtrafusalfibers（梭外肌纖維）:InnervatedbyalphamotorneuronsIntrafusalfibers（梭內(nèi)肌纖維）:InnervatedbygammamotorneuronsTwoTypesofMuscleFibersExtrafusalfibers（梭外肌纖維）:InnervatedbyalphamotorneuronsIntrafusalfibers（梭內(nèi)肌纖維）:Innervatedbygammamotorneurons肌索（musclespindle）:感受肌肉長(zhǎng)度變化信息的感受裝置TwoTypesofMuscleFibersAlphaMotorNeuron:Aneuronwhoseaxonformssynapseswithextrafusalmusclefibersofaskeletalmuscle:activationcontractsthemusclefibers.Motorunit（運(yùn)動(dòng)單位）:MotorneuronandallthemusclefibersitinnervatesMotorneuronpool（運(yùn)動(dòng)神經(jīng)元池）:AllthemotorneuronsthatinnervateasinglemuscleLowerMotorNeurons ALS:amyotrophiclateralsclerosis肌萎縮性側(cè)索硬化癥ALSisaprogressivefataldiseasecausedbydegenerationoflowermotorneuronsinthelateralhornofthespinalcordanduppermotorneuronsofthecerebralcortex,resultinginprogressivemotorweakness14ALS:amyotrophiclateralsclerosisLouGehrig15ALS:amyotrophiclateralsclerosisLouGehrigStephenHawking16NeuromuscularjunctionExcitation-ContractionCouplingMuscleContractionAlphamotorneuronsreleaseAChAChproduceslargeEPSPinmusclefiberEPSPevokesmuscleactionpotentialActionpotentialtriggersCa2+releaseFibercontractsCa2+reuptakeFiberrelaxesExcitation-ContractionCouplingMyastheniaGravis

（重癥肌無(wú)力）MGischaracterizedbyweaknessandfatigabilityofvoluntarymuscles,typicallyincludingthemusclesoffacialexpressionMGisanautoimmunedisease.Theimmunesystemofafflictedindividualsgeneratesantibodiesagainstthebody’sownnicotinicAchreceptorsEffectivetreatmentsincludeAChEinhibitorsorsuppressionoftheimmunesystem19InputstoAlphaMotorNeuronsLowerMotorNeurons Dorsalrootganglioninputfrommusclespindle.Providesfeedbackaboutmusclelength.Uppermotorneuronsinthemotorcortexandbrainstem.Voluntarycontrolofmuscles.InterneuronsSpinalControlofMotorUnits

運(yùn)動(dòng)單位的脊髓控制Proprioceptionfrommusclespindles來(lái)自肌索的本體感覺(jué)ProprioceptionfromGolgitendonorgans來(lái)自高爾基腱器官的本體感覺(jué)Spinalinterneurons脊髓中間神經(jīng)元21Sensoryfeedbackfrommusclespindles-stretchreceptorSpinalControlofMotorUnits22GolgiTendonOrgans Additionalproprioceptiveinput-actslikestraingauge-monitorsmuscletensionSpinalControlofMotorUnits高爾基腱器官：感受張力變化信息SpinalInterneuronsSynapticinputstospinalinterneurons:PrimarysensoryaxonsDescendingaxonsfrombrainCollateralsoflowermotorneuronaxonsOtherinterneurons

SpinalControlofMotorUnits24小結(jié)SpinalcontrolofmovementDifferentlevelsofanalysisSensationandmovementlinked:DirectfeedbackIntricatenetworkofcircuits25BrainControlofMovement

運(yùn)動(dòng)的腦部控制

26DescendingSpinalTracts

（下行脊髓束）27CerebralMotorCortex

（大腦運(yùn)動(dòng)皮層）運(yùn)動(dòng)皮層（MotorCortex）：初級(jí)運(yùn)動(dòng)皮層、前運(yùn)動(dòng)皮層、輔助運(yùn)動(dòng)皮層Area4andarea6ofthefrontallobe2829DescendingSpinalTracts

下行脊髓束AxonsfrombraindescendalongtwomajorpathwaysLateralPathways外測(cè)通路VentromedialPathways腹內(nèi)側(cè)通路30TheLateralPathwaysVoluntarymovement-originatesincortex（皮層）ComponentsCorticospinaltract(皮層脊髓束)Rubrospinaltract（紅核脊髓束）DescendingSpinalTracts31TheVentromedialPathwaysPostureandlocomotion-originatesinbrainstem（腦干）TheVestibulospinaltract（前庭脊髓束）:headbalance,headturningTheTectospinaltract（頂蓋脊髓束）:orientingresponseDescendingSpinalTracts32TheBasalGanglia基底神經(jīng)節(jié)BasalGanglia:Selectionandinitiationofwilledmovements33BasalGangliaMotorCircuitInputpathwaytobasalganglia:cerebralcortexandsubstantianigraOutputpathwayofbasalganglia:cortexandbrainstem34BasalGangliaDisordersParkinson’sdisease(PD)Huntington’sdisease(HD)35ClinicalFeaturesofPD36PathologicalHallmarksofPDLossofdopaminergicneuronsinthesubstantianigraparscompacta(SNpc)37NigrostriatalPathwayDeficitsinPDNeuron,200338LossofdopamineneuronsinParkinson’sdiseaseStriatumMotorCortexMotorThalamusPremotorCortex+Glutamate-GABAGPeGPi/SNrSTNDopamineSNc+-X39EtiologyofParkinson’sDiseaseEnvironmentaltoxinhypothesis

MPTP(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine):aneurotoxinprecursortoMPP+,whichcausespermanentsymptomsofParkinson'sdiseasebydestroyingdopaminergicneuronsinthesubstantianigraofthebrain.

Rotenone:

pesticide魚(yú)藤酮Paraquat:herbicide百草枯

Maneb:fungicide代森錳

40EtiologyofParkinson’sDiseaseGenetichypothesis

SNCA:encodingα-synuclein

PARK2:encodingtheE3ubiquitinligaseparkin

PARK6:encodingPINK1,amitochondrialkinase

PARK7:encodingtheproteinDJ-1

PARK8:encodingleucine-richrepeatkinase2(LRRK2)

PARK9:encodingATP13A241FurtherreadingifyouareinterestedinParkinson’sdisease42Huntington’s

Disease

Huntington'sdisease.HDisaprogressiveneurodegenerativedisordercausedbyexpansionofaCAGrepeatcodingforpolyglutamineintheNterminusofthehuntingtinprotein.Polyglutamine(PolyQ)Repeat>40repeatsinHD44Huntington’s

Disease

Selectivelossofindirect-pathwayneuronsinHuntington’sDiseaseStriatumMotorCortexMotorThalamusPremotorCortex+Glutamate-GABAGPeGPi/SNrSTNDopamineSNc+-X46FunctionsInvolvedincontrolofsmoothandaccuratemovementsClumsymovementresultsfromdysfunctionInvolvedincontrolofeye-handcoordination,movementtiming,postureServesasatypeofmovementerrordetectionandcorrectionsystemReceivescopyofmotorneuralsignalssentfrommotorcortextomusclesInvolvedinlearningmotorskillsTheCerebellum47TheCerebellumCerebellarlesions小腦損傷Ataxia（共濟(jì)失調(diào)）:UncoordinatedandinaccuratemovementsDyssynergia（痙攣）:DecompositionofsynergisticmultijointmovementsDysmetria（測(cè)距不準(zhǔn)）:Overshootorundershoottarget48AnatomyoftheCerebellumTheCerebellum49SummaryLowermotorneuronswerecontrolledbycerebralcortexandbrainstemBasalganglionandcerebellummodulatemovementsDisordersassociatedwithmovements50Questions1.Cerebellumandbasalganglioncontrolmovementsdirectly()2.Whichofthefollowingneuralstructuresisnotinvolvedincontrollingmovements()A.spinalcordB.brainstemC.hypothalamusD.cerebralmotorcortex3.Whichofthefollowingisnotbelongtothebasalganglion()A.caudatenucleusB.PutamenC.GlobuspallidusD.amygdala4.Motorunit5.Motorneuronpool6.Listthecomponentsofthelateralandventromedialdescendingspinalpathways.Whichtypeofmovementdoeseachpathcontrol?51ThankYou52IntroductionMotorProgramsMotorsystem:MusclesandneuronsthatcontrolmusclesRole:GenerationofcoordinatedmovementsPartsofmotorcontrolSpinalcordcoordinatedmusclecontractionBrainactivatemotorprogramsinspinalcord53TheSomaticMotorSystem

TypesofMusclesSmooth:digestivetract,arteries,relatedstructuresStriated:Cardiac(heart)andskeletal(bulkofbodymusclemass)54TypesofMotorUnitsFastmotorunits:Rapidlyfatiguingwhitefibers(Fewmitochondria,anaerobicmetabolism,contractandfatiguerapidly)Slowmotorunits:Slowlyfatiguingredfibers(Largenumberofmitochondriaandenzymes,slowtocontract,cansustaincontraction)LowerMotorNeurons 55GammaLoopKeepsspindle“onair”ChangessetpointofthemyotaticfeedbackloopAdditionalcontrolofalphamotorneuronsandmusclecontractionSpinalControlofMotorUnitsExcitatoryInputCrossed-extensorreflex:Activationofextensormusclesandinhibitionofflexorsonoppositeside

SpinalControlofMotorUnits57GeneratingSpinalMotorProgramsforWalkingCircuitryforwalkingresidesinspinalcordRequirescentralpatterngeneratorsSpinalControlofMotorUnits58TheMotorLoopThroughtheLateralCerebellumCalibratedexecutionofplanned,voluntary,multijointmovementsTheCerebellum59ThePlanningofMovementbytheCerebralCortexTheContributionsofPosteriorParietalandPrefrontalCortex(Cont’d)Anteriorfrontallobes:Abstractthought,decisionmakingandanticipatingconsequencesofactionArea6:Actionsconvertedintosignalsspecifyinghowactionswi