神经元和神经胶质细胞神经元精品文稿.ppt

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1、神经元和神经胶质细胞神经元第1页，本讲稿共30页OneoftheCajalsOneoftheCajalsmanydrawingsofmanydrawingsofBraincircuityBraincircuityTheletterslabelthedifferentelementsCajalidentifiedinanareaofthehumancerebralcortexthatcontrolsvoluntarymovement.第2页，本讲稿共30页Neurons:Excitablecells“wiring”“SignalSenders”Neuroglia:Support,Nurturin

2、g,InsulationCellularComponentsCellularComponents第3页，本讲稿共30页NerveCellsNerveCellsNeuronsNeuroglia第4页，本讲稿共30页Cellbody(soma;perikaryon)Axon:onlyone(branchesarecollaterals;terminalsareendfeet)Dendrites:muchshorter;oneormorethanone;branchextensivelyintodendritictreesStructureofNeuronsStructureofNeuronsAxo

3、nHillock(Axonalendfeet)第5页，本讲稿共30页TheAxonTheAxonandAxonandAxonCollateralsCollaterals第6页，本讲稿共30页CellBody(Soma):LifeSupportProteinSynthesisSingleNucleus,RER(NisslBodies)Axon:LongestprocesstransmitsmessagesawayfromcellbodyDendrites:MultipleprocessesoffcellbodyreceivemessagesNeuronsNeuronsStructure&Func

4、tionStructure&Function第7页，本讲稿共30页Neuronsaresimilartoothercellsinthebodyinsomewayssuchas:1.Neuronsaresurroundedbyamembrane.2.Neuronshaveanucleusthatcontainsgenes.3.Neuronscontain:Whatareinsideofaneuron?Whatareinsideofaneuron?NucleusNucleolusMicrofilaments/NeurotubulesEndoplasmicReticulum(ER)Mitochond

5、riaGolgiApparatusNisslBodiesOthers第8页，本讲稿共30页Dendrites:dendritetreeAxon:axonhillock(axonorigination)axonaltransportsysteminitialsegment(firstmyelinsheath)actionpotentialgenerationmyelinsheathAxonandDendritesAxonandDendrites第9页，本讲稿共30页AxonsDendritesTakeinformationawayfromthecellbodyTakeinformationtot

6、hecellbodySmoothsurfaceRoughsurface(dendriticspines)Generallyonly1axonpercellUsuallymanydendritespercellNoribosomeHaveribosomesCanhavemyelinNomyelininsulationBranchfurtherfromthecellbodyBranchnearthecellbodyDifferencesbetweenAxonsandDendrites第10页，本讲稿共30页NeuronClassificationbyShapeNeuronClassificatio

7、nbyShapeMultipolar:“multi-”manyprocessesMajority:Singleaxon,manydendrites(motorneuronandinterneuron)Bipolar:“bi-”2processesFoundinsomesensoryorgans(retina,taste,smell,innerearneuron)Unipolar(pseudo-unipolar):“uni-”1process(withbranches)Sensoryafferentneurons(dorsalrootganglia)第11页，本讲稿共30页Classificat

8、ionofClassificationofNeuronsbyNeuronsbyMorphologyMorphology第12页，本讲稿共30页ClassificationofNeuronsClassificationofNeuronsbyAxonLengthbyAxonLength1.GolgitypeINeuronsLongaxons(longestfromthecortextothetipofspinalcord,50-70cm)2.GolgitypeIINeuronsShortaxons(shortestaxonsterminateonlyafewmicronfromcellbody,i

9、nterneurons)3.AmacrineNeuronsAnunusualcelltype,lackaxons第13页，本讲稿共30页SensoryneuronfromreceptortoCNS;receivestimuliandtransmitafferentimpulsestoCNSInterneuronscommunicatingbetweenneurons;formcircuitsintheCNSMotorneuronfromCNStoeffectorcells;deliverefferentimpulsesoutthroughthePNStotheeffectorstocarryo

10、uttheactionsdirectedbytheCNSFunctionalClassificationofNeuronFunctionalClassificationofNeuron第14页，本讲稿共30页EXCITABLEMembrane:Abletoregulatethemovementofions(charges)acrossandalongmembraneSIGNAL TRANSDUCTIONDONOTReplicate:Damagedcellscannotbereplaced!ImportantFeaturesImportantFeatures ofof NeuronsNeuron

11、s第15页，本讲稿共30页ActionActionPotentialPotential第16页，本讲稿共30页FourFunctionalRegionsofModelNeuronsFourFunctionalRegionsofModelNeurons第17页，本讲稿共30页Impulsetransmission:electricalchemicalMorphology:axodendriticaxonsomaticaxoaxonicdendrodendriticClassificationofSynapsesClassificationofSynapses第18页，本讲稿共30页synapse

12、4VesiclesreleaseNeurotransmitters第19页，本讲稿共30页Chemicalsynapse:presynapticknob(presynapticcomponent)synapticvesiclessynapticcleftpostsynapticmembrane(postsynapticcomponent)Electricalsynapse:gapjunctionsSynapseStructuresSynapseStructures第20页，本讲稿共30页第21页，本讲稿共30页 TypesofsynapseDis-tanceCytoplasmiccontinu

13、ityUltrastruct-uralcomponentAgentoftrans-missionSynapticdelayDirectionoftrans-missionElectrical3.5 nmYesGap-junctionchannelIoncurrentVirtuallyabsentUsuallybidirectionalChemical20-40 nmNoPresynapticvesicleandactivezone;postsynapticreceptorsChemicaltransmittersSignificant:atleast0.3ms;usually1-5msorlo

14、ngerUni-directionalDistinguishingPropertiesofDistinguishingPropertiesofElectricalandChemicalSynapsesElectricalandChemicalSynapses第22页，本讲稿共30页Atachemicalsynapse,neuronstransmitinformationacrossacleft.第23页，本讲稿共30页1.SmallMoleculeNeurotransmitterSubstancesAcetylcholine(ACh);Dopamine(DA);Norepinephrine(N

15、E);Serotonin(5-HT);Histamine2.AminoAcidsGamma-aminobutyric acid(GABA);Glycine;Glutamate;Aspartate3.NeuroactivePeptides-partiallist!Bradykinin;beta-endorphin;calcitonin;cholecystokinin;enkephalin;dynorphin;insulin;gastrin;substance P;glucagon;secretin;vasopressin;oxytocin,etc.ListofSomeNeurotransmitt

16、ersListofSomeNeurotransmitters第24页，本讲稿共30页Axonaltransport:intracellularcommunicationBidirectionalmechanism:anterogradetransportretrogradetransportClassifiedbytransportrates:slowtransportsystem(0.2to1mm/day)fasttransportsystem(200to400mm/day)AxonalTransportSystemsAxonalTransportSystems第25页，本讲稿共30页Hit

17、chingaRideon“Retrorail”第26页，本讲稿共30页MembranesoforganellesinvolvedinsynaptictransmissionarereturnedtothecellbodyforreuseordegradationNucleusCytoskeleton(Anterogradetransport)第27页，本讲稿共30页第28页，本讲稿共30页ComponentRate(mm/day)StructureandcompositionFasttransportAnterograde 200-400Smallvesiculotubularstructur

18、es,neurotransmitters;membraneproteinsandlipidsMitochondria50-100MitochondriaRetrograde 200-300LysosomalvesiclesandenzymesSlowtransportSCb2-8Microfilaments,metabolicenzymes,clathrincomplexSCa0.2-1NeurofilamentsandmicrotubulesMajorRateComponentsofAxonalTransportMajorRateComponentsofAxonalTransport第29页

19、，本讲稿共30页1.Neuronshavespecializedprojectionscalleddendritesandaxons.Dendritestakeinformationtothecellbodyandaxonstakeinformationawayfromthecellbody2.Neuronscommunicatewitheachotherthroughanelectrochemicalprocess3.Neuronscontainsomespecializedstructures(likesynapses)andchemicals(likeneurotransmitters)4.NisslBodies5.DONOTReplicate:Damagedcellscannotbereplaced!NeuronsdifferfromOtherCellsNeuronsdifferfromOtherCells第30页，本讲稿共30页