乙酰膽堿和其他神經(jīng)遞質(zhì)專家講座

乙酰膽堿和其它神經(jīng)遞質(zhì)ZhuCui-Qing.101乙酰膽堿和其他神經(jīng)遞質(zhì)第1頁Chapter6:Acetylcholine

乙酰膽堿2乙酰膽堿和其他神經(jīng)遞質(zhì)第2頁GeneralknowledgeHistoryofAChasaneurotransmitter:1867:Chemicallysynthesized.乙酰膽堿3Dale(1914):theeffectofAChontheheartissimilarwiththatofvagalstimulation

Loewi(1921)、Dale（1924):infusionexperimentoffrogheart.1936:NobelPrize.乙酰膽堿和其他神經(jīng)遞質(zhì)第3頁Conceptofcholinergicneurons:Neuronsthatuseacetylcholineastheneurotransmitter.GeneralknowledgeChemicalpropertyofacetylcholine：a.Easilyhydrolyzed:stableatpH3.8-4.5；completehydrolysisatpH10and100°C.b.Easilycatalyticallyhydrolyzedbycholinesterase.生物學作用即時性生物樣品保留和檢測4乙酰膽堿和其他神經(jīng)遞質(zhì)第4頁Indirectmethods：a.Measureofcholinesteraseactivity：Acetylthiocholine(乙酰硫代膽堿法,AChE法）.b.ChAT:1970’s,ChATmultiplecolonialantibody;Eckenstein(1981)ChATmonoclonalantibody.Houser(1983):ConsistenceofAchEmethodandChATmethod.DirectmethodsRIA;ELISAChromatogram;HPLCetal.Imunohistology+fluorescenttracing.MeasureofacetylcholineGeneralknowledge5乙酰膽堿和其他神經(jīng)遞質(zhì)第5頁6SectionI:DistributionandprojectionofcholinergicneuronsintheCNS分布與投射Classificationofcentralcholinergicneurons：ProjectionneuronLocalcircuitneuronACh神經(jīng)元分布在哪里？乙酰膽堿和其他神經(jīng)遞質(zhì)第6頁(I)基底前腦膽堿能系統(tǒng)(basalforebraincholinergicsystem)Mesulam和Perry分群：ch1-ch6。Ch1、Ch2、Ch3分別相當于隔內(nèi)側(cè)核（medialseptalnucleus）、斜角帶垂直部（verticalnucleusofthediagonalband）、斜角帶水平部（horizontallimbofthediagonalband）；Ch4則包含了視前大細胞區(qū)、蒼白球底板無名質(zhì)及其向前延伸蒼白球腹側(cè)區(qū)（紋狀體下灰質(zhì)）、Meynert基底核（nucleusbasalisofMeynert）、豆狀攀核等界限并不很清楚區(qū)域。I.膽堿能投射神經(jīng)元(Projectionneuron)7乙酰膽堿和其他神經(jīng)遞質(zhì)第7頁基底前腦膽堿能系統(tǒng)(basalforebraincholinergicsystem)主要投射通路：它們投射纖維主要形成以下通路：①隔內(nèi)側(cè)核、斜角帶-海馬通路；②斜角帶-杏仁復合體通路；③隔區(qū)-僵內(nèi)側(cè)核（medialhabenula）、中腦腳間核通路；④斜角帶、Meynert基底核-大腦皮層通路。其中由Meynert基底核向皮質(zhì)額葉、顳葉、頂葉和視皮層膽堿能投射，與學習和記憶功效親密相關(guān)。①②③④8④乙酰膽堿和其他神經(jīng)遞質(zhì)第8頁(II)腦干膽堿能系統(tǒng)(brainstemcholinergicsystem)

由腦橋被蓋膽堿能系統(tǒng)（pontinetegmentalcholinergicsystem）和延髓膽堿能神經(jīng)元組成。纖維：背側(cè)被蓋束和腹側(cè)被蓋束，向頭端投射至丘腦、丘腦下部、蒼白球、尾殼核等，并與其它上行纖維一起組成網(wǎng)狀上行激活系統(tǒng)，引發(fā)覺醒和警覺。腦橋被蓋膽堿能系統(tǒng)主要包含腳間腦橋被蓋區(qū)（pedunculopontinetegmentalregion,ppt）和背外側(cè)或外側(cè)被蓋核（dorsolateralorlaterodorsaltegmentalnucleus,ldt）中膽堿能神經(jīng)元，相當于Mesulam和Perry分群中Ch5、Ch6。I.膽堿能投射神經(jīng)元(Projectionneuron)9乙酰膽堿和其他神經(jīng)遞質(zhì)第9頁10乙酰膽堿和其他神經(jīng)遞質(zhì)第10頁中腦和腦橋動眼神經(jīng)（III）、滑車神經(jīng)（IV）、外展神經(jīng)（VI）膽堿能運動神經(jīng)元胞體。延髓膽堿能神經(jīng)元主要分布：舌下神經(jīng)核（XII）、迷走神經(jīng)背核與疑核（X）、面神經(jīng)核（VII）、三叉神經(jīng)脊束核（V）11乙酰膽堿和其他神經(jīng)遞質(zhì)第11頁I.膽堿能投射神經(jīng)元(Projectionneuron)(III)Cholinergicneuronsinthespinalcord脊髓前腳運動神經(jīng)元側(cè)角交感和副交感節(jié)前神經(jīng)元12乙酰膽堿和其他神經(jīng)遞質(zhì)第12頁局部環(huán)路神經(jīng)元這類神經(jīng)元在核團內(nèi)局部組成環(huán)路，不向核外發(fā)出投射，屬中間神經(jīng)元。紋狀體（尾-殼核復合體，Caudate-putamencomplex）、伏隔核(nucleusaccumben)、嗅結(jié)節(jié)（olfactorytubercle）、海馬和大腦皮質(zhì)內(nèi)Ⅱ-Ⅴ層。紋狀體內(nèi)膽堿能神經(jīng)元主要為大、中型無棘突多極神經(jīng)元，參加黑質(zhì)-紋狀體多巴胺系統(tǒng)對運動調(diào)整，其異常與帕金森氏?。≒arkinson’sDisease,PD）病理過程親密相關(guān)。孤束核、前庭外側(cè)核、外側(cè)網(wǎng)狀核、巨細胞網(wǎng)狀核、中縫大核等。脊髓背角膽堿能神經(jīng)元投射到脊髓RexedⅡ-III層、小腦內(nèi)第Ⅱ?qū)宇w粒細胞投射到Ⅴ層細胞也形成局部環(huán)路。II.Localcircuitneuron13乙酰膽堿和其他神經(jīng)遞質(zhì)第13頁基底前腦乙酰膽堿能系統(tǒng)(basalforebraincholinergicsystem)主要投射通路有哪些？皮層和海馬是否有乙酰膽堿能神經(jīng)元？Question

114乙酰膽堿和其他神經(jīng)遞質(zhì)第14頁-S-(I)BiosynthesisCholineAcetylcoenzymeACholineacetyltransfease膽堿乙酰轉(zhuǎn)移酶Cholineacetylase膽堿乙?；窼ubstrates:膽堿乙酰輔酶ASectionII:biosynthesis,storageandrelease15乙酰膽堿和其他神經(jīng)遞質(zhì)第15頁ChAT,globulin,MW68000.Synthesizedincellbody,takeseffectinterminals.Essentialchemicalgroups:imidazole,-SH.Enzymedynamics(Km)：choline7.5×10-4mol/L;AcetylCoA1.0×10-5mol/L.Siteofsynthesis合成部位：CholinergicterminalsEnzyme:(I)Biosynthesis16乙酰膽堿和其他神經(jīng)遞質(zhì)第16頁ChAT咪唑基乙?；D(zhuǎn)乙酰作用活性中心：咪唑基巰基AcetylcoenzymeACholine(I)BiosynthesisCholineacetyltransfease膽堿乙酰轉(zhuǎn)移酶ChATCholineacetylase膽堿乙?；?7乙酰膽堿和其他神經(jīng)遞質(zhì)第17頁1.AcetylCoA.Source:(1)glucose-pyruvicacid-AcetylCoA.

（2）Fattyacidb-oxidation.

（3）synthesizedfromcitricacid.(4)acetate(non-neuraltissues)Substrate:(I)Biosynthesis18乙酰膽堿和其他神經(jīng)遞質(zhì)第18頁2.CholineSource:

a.uptakeandhydrolyzelecithinfromcirculation.b.hydrolysisoflecithinofneuronaltissues.c.hydrolysisofAchandreuptakeofcholine.1/3-1/2.卵磷脂(I)BiosynthesisSubstrate:19乙酰膽堿和其他神經(jīng)遞質(zhì)第19頁

Lowaffinitycarrier:distributedinallneuronsandgliacells.Km:40-100micromol/L.facilitateddiffusionTransportationofcholine:Highaffinitycarrierspecificallydistributedincholinergicterminals.Km:0.4-4micromol/LNa+,ATP-dependentactivetransportation.Satureduptake.Themosteffectivelimitfactorofacetylcholinesynthesis(!).Cholineisthelimitsubstrate.(I)Biosynthesis20乙酰膽堿和其他神經(jīng)遞質(zhì)第20頁Hemicholium-3(HC-3)密膽堿Mechanism：competehighaffinitycarrierwithcholine.Antagonizedbycholine.

神經(jīng)末梢characteristics：unabletopassthoughblood-brainbarrier;centraladministrationneeded.Strong,slow,lastingeffect.Triethylcholine三乙基膽堿(CH3CH2)3N+-(CH2)2-OHMechanism：synthesisoffakeneurotransmitter，inadditiontocompetingwithcholineforuptake4-(1-naphthylvinyl)pyridine]

4-(1-萘乙烯基)吡啶Mechanism：：specificChATinhibitorinvitro.AgentsaffectingthebiosynthesisofACh(I)Biosynthesis21乙酰膽堿和其他神經(jīng)遞質(zhì)第21頁試述乙酰膽堿生物合成主要底物、以及影響乙酰膽堿生物合成主要原因。怎樣調(diào)整乙酰膽堿合成?Question

222乙酰膽堿和其他神經(jīng)遞質(zhì)第22頁ATP--vesicleprotein---Ach+VesicleAcetylcholineTransporter(VAChT)(II)StorageandreleaseStorage:膽堿能神經(jīng)元標志高濃度質(zhì)子泵23乙酰膽堿和其他神經(jīng)遞質(zhì)第23頁Release:PhosphorylationanddephosphorylationofsynapsinIinregulationofreleasableandreservepoolsofvesicles.(II)StorageandreleaseCa++synapsinIactinActivezoneofsynapse.24穩(wěn)定池不穩(wěn)定池盈余池乙酰膽堿和其他神經(jīng)遞質(zhì)第24頁Electrophysiologicalobservations:-restingneuromuscularjunctionsoftenhadspontaneousminiatureendplatepotentials(mepps)oflessthan1mVinamplitude.微小（最?。┙K板電位amplitudeofstimulatedeppweremultiplesofthemepps.Conclusion:-transmitterisreleasedindiscreteunits(quanta).-smallestmepprepresentsthereleaseof1quanta.(II)StorageandreleaseEvidenceofquatarelease:25乙酰膽堿和其他神經(jīng)遞質(zhì)第25頁2.ElectronmicroscopyEvidenceofquatarelease:Freeze-fractureelectronmicrograph26乙酰膽堿和其他神經(jīng)遞質(zhì)第26頁3.NeurochemistryNa+K+Ca2+VSCCreleaseeffluxLactatedehydrogenase*Evidenceofquatarelease:4.CloningofVAChTandfindingitsblockervesamicolQuestion3什么是量子釋放？依你所知，有哪些證據(jù)證實神經(jīng)遞質(zhì)是以量子方式釋放？檢測-釋放量27乙酰膽堿和其他神經(jīng)遞質(zhì)第27頁SNAP-25SYNTAXINSynaptobrevin(VAMP)Botulinumtoxin肉毒桿菌毒素Tetanus

toxin破傷風毒素-bungarotoxin-bungarotoxinH+vesamicol銀環(huán)蛇毒素α-BGT與運動終板乙酰膽堿受體結(jié)合，抑制乙酰膽堿對橫紋肌細胞膜去極化作用，橫紋肌松弛。β-BGT作用于運動神經(jīng)突觸前膜產(chǎn)生一個三相改變，1）遞質(zhì)釋放降低，2）釋放增加，3）隨即是深入抑制，使骨骼肌不能興奮收縮而轉(zhuǎn)入連續(xù)性麻痹，其毒性比突觸后毒素高得多。運動終板Blackwidowspidervenom1）阻斷SNARE蛋白分離2）形成離子通道28乙酰膽堿和其他神經(jīng)遞質(zhì)第28頁TransmitterisGLYCINETransmitterisACETYLCHOLINEBotulinumToxin29乙酰膽堿和其他神經(jīng)遞質(zhì)第29頁Specificcholinesterase(AchE)：mainlyinneuraltissues。Non-Specificcholinesterase(butyrylcholinesterase):gliacells,non-neuraltissues.I.Enzymaticdecompositionandinactivation乙酰膽堿酯酶-水解速度106Ach/S丁酰膽堿酯酶SectionIII:Enzymaticdecompositionandinactivation30StructureofAchE1)Anionsite:imidazolegroupofhistidine(組氨酸）.2)SiteofEnzymaticdecomposition:-OHofserine,nucleophilic乙酰膽堿和其他神經(jīng)遞質(zhì)第30頁（I）reversiblePhysostigmine,毒扁豆堿neostigmine:新斯明

為含季銨基團氨基甲酸酯類。Edrophonium:Edrophoniumchloride依酚氯銨：

含季銨基團，但無氨基甲?；?。起效快，作用短。（II）irreversible:organicphosphoruspesticide,chemicalwarfareagent（VX,沙林）II.Cholinesteraseinhibitors31乙酰膽堿和其他神經(jīng)遞質(zhì)第31頁有機磷農(nóng)藥32乙酰膽堿和其他神經(jīng)遞質(zhì)第32頁生化武器33乙酰膽堿和其他神經(jīng)遞質(zhì)第33頁antidotestoanticholineesterasessymptomatic“antidote”-atropinepralidoxime(2-PAM)解磷定BACD解毒劑A氯磷定(2-PAM·Cl)

B雙復磷(LüH-6)

C甲磺磷定(P2S)

D雙磷定(TMB-4)1.2.直接與有機磷結(jié)合34解毒：乙酰膽堿和其他神經(jīng)遞質(zhì)第34頁Alzheimer’sdisease四氫氨基吖啶（tetrohydroaminoacridine）

TacrineHydrochloride35抑制膽堿酯酶藥用價值乙酰膽堿和其他神經(jīng)遞質(zhì)第35頁SectionIV:CholinergicReceptorsAch一些效應可被毒蕈堿（muscarine）模擬而被阿托品阻斷另一些效應可被煙堿（nicotine）模擬而被箭毒（curare）阻斷36乙酰膽堿和其他神經(jīng)遞質(zhì)第36頁I.Muscarinicreceptor1.G蛋白偶聯(lián)2.7次跨膜3.差異--大環(huán)4.兩類M1,3,5;M2,437乙酰膽堿和其他神經(jīng)遞質(zhì)第37頁Meffects:

1)Inhibitingheart(M2)todecreaseheartrate,conductionandcontractility.

2)Vasodilationofartery(M1血管內(nèi)皮--

NO）

3)Contractionofbronchial,gastrointestinalandgenitourinarysmoothmuscles,butrelaxationofsphincters

4)Increasing

secretion(M3)ofsalivary,respiratoryandgastrointestinaltractglands

5)Eye(M3):miosis.nearvision.泌尿生殖器括約肌瞳孔縮小38外周效應乙酰膽堿和其他神經(jīng)遞質(zhì)第38頁M1，3，4receptors----cortex,hippocampus—learningandmemoryM1,4receptors----striatum–extrapyramidalmotorcircuitsM2–basalforebrain—autoreceptorstocontrolAChsynthesisandreleaseM5istheleastabundant—Substantianigra.Mreceptorantagonists(trihexyhenidylandbenztropine)areprescribedtoPDpatients苯海索苯托品Tricyclicantidepressantsandlow-potencyantipsychoticdrug(chlorpromazine氯丙嗪)antagonizeMreceptors中樞M受體分布東莨菪鹼M1andM2MuscarinicReceptorSubtypesRegulateAntidepressant-LikeEffectsoftheRapidlyActingAntidepressantScopolamineJPharmacolExpTher351:448–456,39乙酰膽堿和其他神經(jīng)遞質(zhì)第39頁II.Nicotinicreceptor40乙酰膽堿和其他神經(jīng)遞質(zhì)第40頁Purificationofcholinergicreceptors

金環(huán)蛇Bungarusfasciatus銀環(huán)蛇Bungarusmulticinctus41應用金銀環(huán)蛇毒素乙酰膽堿和其他神經(jīng)遞質(zhì)第41頁PurificationofreceptorsCarb-nAchRTorpedoelectricorgannAchRnAchRnAchRsolubilizationHomogenizationCarbamylcholineSequenceanalysisofsegmentsSynthesisofprobeRNAa-BTXReconstructioninlipidbilayer(functional?)電鰩42氨基甲酰膽堿洗脫乙酰膽堿和其他神經(jīng)遞質(zhì)第42頁cDNAlibraryscreeningLowdensityreceptorsintissueIsolatetotalRNAsIsolatemRNAsprobeRNAcDNAlibraryInvitrotranscriptionofthecDNAlibraryInjectionofcRNAsintoXenopusoocytesElectrophysiologicalmeasurementofligand-inducedcurrent SequencingInjectionofcRNAsintoXenopusoocytesPCR43HomologyscreeningTorpedoelectricorgan乙酰膽堿和其他神經(jīng)遞質(zhì)第43頁SubunitsofAchRare4TMHydropathyindexanalysis44乙酰膽堿和其他神經(jīng)遞質(zhì)第44頁thesuperfamilyofcys-loopreceptors親水面形成離子通道內(nèi)壁45乙酰膽堿和其他神經(jīng)遞質(zhì)第45頁TM2segmentisthepore-liningdomainofAchR46乙酰膽堿和其他神經(jīng)遞質(zhì)第46頁Structureandfunctions：Membrane-bindingglucoprotein.Fivehomologoussubunits(1,

,1,1,)makeupthechannel.Eachsubunitshasfour-helicalmembranespinningdomains(M1-M4),andM2domainofeachsubunitmakeupthelinenofthechannel.ThetwosubunitsarethebindingsitesforACh

(-BGTX)Bothareceptorandachannel,mediatesfastsignaling.(I)Peripheralnicotinicreceptors47乙酰膽堿和其他神經(jīng)遞質(zhì)第47頁Ach功效？48解剖位置屬于外周受體分型屬于中樞乙酰膽堿和其他神經(jīng)遞質(zhì)第48頁NolossofAPinnervecellsAristotleOnassislossofmuscletoneMG-myastheniagravisAutoimmunedestructionofacetylcholinereceptorsnAChRHinderACh-receptorinteractionIncreasereceptorturnoveranddegradationTreatment:AChEinhibitors,glucocorticoidsorotheragentstosuppressimmunefunction重癥肌無力機制49乙酰膽堿和其他神經(jīng)遞質(zhì)第49頁試述外周尼古丁型乙酰膽堿受體結(jié)構(gòu)和功效特點Question450乙酰膽堿和其他神經(jīng)遞質(zhì)第50頁（II）Centralnicotinicreceptors(includingganglion)Subunitcompositionofcentralnicotinicreceptors:2-10(theperipheralsubunitas1)2-4(theperipheralsubunitas1)About2-6,2-4:Donotformhomomericreceptors,noreceptorswithonlyoronlysubunitsexist.51乙酰膽堿和其他神經(jīng)遞質(zhì)第51頁Commonreceptortypes52乙酰膽堿和其他神經(jīng)遞質(zhì)第52頁Theheteromeric

42

23

subtype:facilitateGABAergicandglycinergicneurotransmission.Insensitiveto-BGTX，sensitivetoKappaorFtoxin.GABAglycine

42

23

42

2353乙酰膽堿和其他神經(jīng)遞質(zhì)第53頁Thehomomeric

75subtype:facilitateglutamatergicneurotransmission.sensitiveto-BGTX.glutamate

75

7含有-BGTX高親和力結(jié)合部位

7-10只形成同聚體（成熟神經(jīng)元細胞表面）54乙酰膽堿和其他神經(jīng)遞質(zhì)第54頁Gardu?oJetal.J.Neurosci.;32:15148-15157?bySocietyforNeuroscience例外Presynapticα4β2nicotinicacetylcholinereceptorsincreaseglutamatereleaseandserotoninneuronexcitabilityinthedorsalraphenucleus.JNeurosci.Oct24;32(43):15148-5755乙酰膽堿和其他神經(jīng)遞質(zhì)第55頁Fig.1(A)PhotomicrographshowingbasalocorticalPHA-L-labeledfibersintheretrosplenialgranularcortex(RSG)followingaseriesofinjectionsofPHA-Lintothemedialpartofthehorizontallimbofthediagonalban(HDBm).PHA-Llabeledfibersarecon...Localizationofα7nicotinicacetylcholinereceptorimmunoreactivityonGABAergicinterneuronsinlayersI–IIIoftheratretrosplenialgranularcortexNeuroscience,Volume252,,443-459N受體在細胞體分布56乙酰膽堿和其他神經(jīng)遞質(zhì)第56頁3,5,72,4makeupthechannel.homomericreceptorscontaining3inmostcondition.Heteromericreceptorscontaining7(胚胎期)(III)Nicotinicreceptorsinautonomicganglions解剖分類屬于外周型亞單位組成屬于中樞57乙酰膽堿和其他神經(jīng)遞質(zhì)第57頁PresynapticnAChRsinducereleaseofanumberofneurotransmittersPostsynapticnAChRsdepolarizeneurons,increasetheirfiringrate,andcancontributetolong-termpotentiation58主要中樞作用乙酰膽堿和其他神經(jīng)遞質(zhì)第58頁興奮效應直接--興奮2.間接？鈣依賴效應與N受體鈣通透激活鄰近電壓依賴性鈣離子通道細胞內(nèi)鈣參加效應。59乙酰膽堿和其他神經(jīng)遞質(zhì)第59頁試述中樞尼古丁型乙酰膽堿受體結(jié)構(gòu)和功效特點Question4Characteristicsofcentralnicotinereceptors:

*Structure，subunits,*highlypermeabletoCa++.consequentlyactivatevoltagegatedCa++channels.*Facilitationofglutamatergicneurotransmissionsby….sensitiveto….

*FacilitationofGABAergicandglycinergicneurotransmission

by…

Insensitiveto…..

60乙酰膽堿和其他神經(jīng)遞質(zhì)第60頁2----Thereinforcingandcognitionenhancingeffects7-----Sensorygating4-----AnalgesiceffectsnAChR中樞功效61？乙酰膽堿和其他神經(jīng)遞質(zhì)第61頁Summaryofmodulatoryeffectsofacetylcholine(ACh)oncorticalcircuitdynamics.ACh與學習記憶關(guān)系62IncreasedAChbooststheprocessingofextrinsicafferentprojections,suppressesintrinsicprojections,andlowersthethresholdfortheinductionofLTP.ReducedAChboostsprocessingofintrinsicprojections,raisesthethresholdfortheinductionofLTPandincreasesthelikelihoodthatLTDisinduced乙酰膽堿和其他神經(jīng)遞質(zhì)第62頁ActivationdynamicsandplasticityinModelofthetafunction.InhibitoryoscillationsconvertdifferencesintheAmountofexcitationreceivedbycellswithinanetworkintoatime(phase)code.Threeexamplecellsareshown,eachreceivingadifferentamountofexcitatoryinput:0.0—thiscellreceivesnoinputandneveractivates,itincursnoLTPorLTD;0.3—thiscellreceivesmoderateinputandactivatesonlyduringthetroughoftheoscillations,itincursLTDasaresult;and0.6—thiscellreceivesstronginputandactivatesduringmorethanhalfoftheoscillation,itincursLTPasaresult.Theta

rhythmismodulatedbycholinergicandGABAergicinputsfromthemedialseptum,andincreasesinacetylcholineareassociatedwiththetaoscillations.Hippocampal

twoseparatefrequencycomponents,acholinergic-independent,movement-relatedthetarhythmat8–9Hz(type1)alowerfrequency6–7Hzcholinergic-dependentcomponent(type2)63乙酰膽堿和其他神經(jīng)遞質(zhì)第63頁RoleofnAChRsindevelopmentThedifferentsubtypesofneuronalnAChRsareknowntobedevelopmentallyexpressedintheratbrainand(particularlyfortheα7subtype)areknowntohaveimportantrolesinthedevelopmentofthehippocampalcircuitry.α7receptorsignaling---thematurationandsurvivalofadult-bornneurons,transformationofGABAergiccurrentsfromexcitatoryinearlydevelopmenttoinhibitorysynapseThecognitivedeficitsassociatedwithADmayberelatedtodysfunctionoftheα7nAChRs.α7nAChRcanundergorapidonsetofdesensitization（channelcloseseveninthecontinuedpresenceofanagonist）.therapeuticdrugsthatpotentiateα7receptorsthroughtheremovalofdesensitization(e.g.,PNU-120596)arecurrentlybeingdevelopedtotreatAlzheimer'sdiseaseandotherneurologicalInthebrain(andinparticularthehippocampus),nicotineorAChactivationoftheα7nAChRblockedthereleaseofproinflammatorycytokines.64膠質(zhì)細胞？乙酰膽堿和其他神經(jīng)遞質(zhì)第64頁Site1: UptakeofcholineSite2: Biosynthesisofacetylcholine(ChAT)，VesicleAcetylcholineTransporter(VAChT).Site3: ReleaseofAch(Note:Thisisnotagoodsiteforthedesignofcholinergicdrugs).Site4: MetabolismofAChbyacetylcholinesterase(AChE)..Site5: PostsynapticandPresynapticreceptors(maintargetfordrugaction).65乙酰膽堿系統(tǒng)干預？乙酰膽堿能神經(jīng)元分布？受體結(jié)構(gòu)和功效特點中樞乙酰膽堿功效乙酰膽堿和其他神經(jīng)遞質(zhì)第65頁SectionI:Histamine組胺Recognitionofhistamineasanintercellularmessenger:注射組胺—過敏(allergy)，呼吸窘迫抗組胺藥廣泛應用于臨床抗組胺藥品鎮(zhèn)靜作用—組胺喚醒Arousal

中樞作用？DistributionPeripheral:mastocyte,basicyte.Central:Neuronalhistamineintuberomammillarynucleus(TMN).Non-neuronalhistamine:gliacell,endothelialcell肥大細胞，嗜堿性細胞Histamine不易經(jīng)過BBB中樞外周獨立Chapter12Otherneurotransmitters66？神經(jīng)營養(yǎng)，神經(jīng)免疫，腦血流，BBB滲透性調(diào)整，等乙酰膽堿和其他神經(jīng)遞質(zhì)第66頁H2-receptorantagonists

asdrugscuringpepticulcerMechanismofactionCompetitivelyblockthehistamine(H2)receptorofacid-producingparietalcells

renderingcellslessresponsivetonotonlyhistaminebutalsotothestimulationofacetylcholineandgastrin.Alsoupto90%inhibitionofvagalstimulatedandgastrinstimulatedacidsecretion.

胃泌激素泌酸細胞FourFDA-approved:Cimetidine西咪替?。═agamet?）Ranitidine雷尼替?。╖antac?）Famotidine法莫替?。≒epcid?）Nizatidine尼扎替?。ˋxid?）Roxatidine羅沙替丁H2-receptorantagonists67乙酰膽堿和其他神經(jīng)遞質(zhì)第67頁1.Histaminetransportandmetabolisminneurons組氨酸脫羧酶，HDC組氨-N-甲基轉(zhuǎn)移酶HNMT單胺氧化酶，醛脫氫酶213456甲基組胺68VMAT-2locatedpostsynapticallyandinglia失活形式HAD抑制劑：

-氟甲基組氨酸，

-FMH乙酰膽堿和其他神經(jīng)遞質(zhì)第68頁2.Histaminergicneurons神經(jīng)元集中，投射廣泛（腦腹側(cè)部為多）突觸:dendrites(predominately),cellbody(less)遞質(zhì)共存常見（GABA,P物質(zhì)）tuberomammillarynucleus(TMN)69乳頭體核結(jié)節(jié)核JCompNeurol.Nov15;518(22):4591–4611.Histidinedecarboxylase(HDC),melanin-concentratinghormone(MCH),andorexin/hypocretins(ORX)乙酰膽堿和其他神經(jīng)遞質(zhì)第69頁70乙酰膽堿和其他神經(jīng)遞質(zhì)第70頁BrainhistamineduringdevelopmentIntherat,theliveristhemainsiteofhistaminesynthesisduringlatestagesoffetaldevelopment,althoughanextensive,transienthistamine-containingneuronalsystemcanbefoundintherapheareaofthebrainduringthisperiod.Thissystemisfirstdetectableonembryonicday14(E14),andatE16,histamineandserotoninshowmarkedcoexistenceintheraphearea.ByE18,histaminelevelsarealreadydiminishedinneuronsoftherapheregion.Histamine-containingmastcellspopulatetheratbrainatE18–E19,andthenumberofthesecellsincreasesuntilpostnatalday4.Therattuberomammillarynucleus(TMN)neuronsarebornbetweenE13andE18,andthatHDC組胺脫羧酶isfirstdetectableintheseneuronsonE18.IntracellularhistamineimmunofluorescencecanbedetectedinTMNneuronsonE2071乙酰膽堿和其他神經(jīng)遞質(zhì)第71頁72ProminentsourcesoftheafferentprojectionstoTMtheinfralimbiccortex,lateralseptumandpreopticnucleus.adrenergiccellgroupsC1–C3,noradrenergicgroupsA1–A3,andfromserotonergicgroupsB5–B9,Themainterminalareasofthehistaminergicprojectionsarealsoslightlydifferentindifferentspecies,buttheycoveressentiallyallareasoftheCNS.下邊緣皮質(zhì):regionintheventromedialprefrontalcortex乙酰膽堿和其他神經(jīng)遞質(zhì)第72頁2.Histaminergicneurons4)Firingproperties:Spontaneouslyactive:pace-makerproperty.

遲緩去極化—動作電位

自發(fā)放電機制:persistentsodiumcurrent，voltage-gatedcalciumcurrent.b.Lowfiringfrequency放電頻率低:LongerAPduration動作電位時程長.Obviousafterhyperpolariztion(AHP):后超極化顯著

機制：voltage-gatedKcurrent,calcium-dependentKcurrent.e.H3autoreceptorsregulatethefiringrate:inhibitionofVDCCs.I-clampV-clampH3激動劑抑制效應乙酰膽堿和其他神經(jīng)遞質(zhì)第73頁(H3receptorantagonist)噻普酰胺<組胺H3受體拮抗藥>反向激動乙酰膽堿和其他神經(jīng)遞質(zhì)第74頁組氨能神經(jīng)元分布電活動特點和機制.Question75乙酰膽堿和其他神經(jīng)遞質(zhì)第75頁3.Histaminergicreceptors組胺受體H1-4,為G蛋白偶聯(lián)受體。H1-3分布于CNS。H1，H2興奮;H3抑制(H3多亞型，Splicing)H4肥大細胞，白細胞，骨髓組織。

原位雜交BindingH1H2H3乙酰膽堿和其他神經(jīng)遞質(zhì)第76頁磷脂酰二肌醇H1-Gq/11磷脂酶C

三磷酸肌醇，甘油二酯

抑制鉀電導H2—Gs腺苷酸環(huán)化酶H3—Gi/o抑制腺苷酸環(huán)化酶

抑制鈣離子通道

本身抑制，抑制其它遞質(zhì)釋放

組胺受體信號通路乙酰膽堿和其他神經(jīng)遞質(zhì)第77頁H1receptors.DepolarizationofaneuronofthepontinereticularformationthroughblockofaK+conductance.H3receptors.Decreaseoffieldexcitatorypostsynapticpotentialinthedentategyrusofthehippocampusevokedbyperforantpathstimulation.Histaminereducedthereleaseofglutamateinthispathway.乙酰膽堿和其他神經(jīng)遞質(zhì)第78頁H2receptors.Blockofthelong-lastingafterhyperpolarizationafterCa2+-inflow(calcium-dependentK+conductance)andblockoftheaccommodationofactionpotentialfiringinahumanhippocampalpyramidalcell.79乙酰膽堿和其他神經(jīng)遞質(zhì)第79頁InteractionsofthehistamineH3receptorwithdopaminereceptors80乙酰膽堿和其他神經(jīng)遞質(zhì)第80頁4.HistamineandthefunctionoftheCNS1)ArousalwakefulnessH1受體相關(guān)證據(jù)：1.組胺能神經(jīng)元活動隨睡眠覺醒周期波動2.組胺釋放有晝夜節(jié)律3.損毀或抑制TM神經(jīng)元造成嗜睡4.腦內(nèi)注射組胺或H1受體激動劑可延長清醒，縮短睡眠。H1拮抗劑阻斷這些效應。

H3拮抗劑有利覺醒81乙酰膽堿和其他神經(jīng)遞質(zhì)第81頁ThehistaminergicTMNnetworkisanessentialcomponentofthesleep–wakeregulatorysystemVentrolateralpreopticnucleus82GABA乙酰膽堿和其他神經(jīng)遞質(zhì)第82頁4.HistamineandthefunctionoftheCNS脫水stressVasopressinreleaseHistamine

-FMH,H3agonists,postsynaptichistmineantagonists(-)2)MaintenanceofendohomeostasisWaterbalance:H1receptor→vasopressinFeeding下丘腦腹內(nèi)側(cè)核（飽中樞）

三叉神經(jīng)核（咀嚼控制）

對leptin功效含有permissiveactionThermalregulation（雙向改變，先降后升）

下丘腦視前區(qū)H1降低體溫調(diào)定點下丘腦后部H2散熱Cardiovascularregulation

升血壓，心率減慢

H2受體-動脈壓力感受器反射

興奮交感神經(jīng)，釋放兒茶酚胺；促釋放AVP83乙酰膽堿和其他神經(jīng)遞質(zhì)第83頁3)Learningandmemory:peoplepredisposedtoallergysmarter?4.HistamineandthefunctionoftheCNS4)Emotionandanxiety5)Painmodulation腦內(nèi)組胺參加焦慮情緒形成外周介導傷害性感受器，介導痛覺在中樞起鎮(zhèn)痛作用腦內(nèi)組胺系統(tǒng)可能是對威脅做出反應系統(tǒng)腦內(nèi)組胺系統(tǒng)興奮可激活交感系統(tǒng)，釋放應激相關(guān)激素。組胺參加神經(jīng)系統(tǒng)疾病機制。84乙酰膽堿和其他神經(jīng)遞質(zhì)第84頁6）Localizationofhistaminereceptorsindifferenttypesofcellsinthebrainthatarepotentiallyinvolvedinblood–brainbarrierpermeabilityandmultiplesclerosis.Hreceptorsinbrainneurons,astrocytes,endothelialcellsandimmunocompetentcellsformacomplexsystemattheinterfaceofbraincapillariesandtheneuropile.Brainendothelialcellsexpressallfourtypesofhistaminereceptors.Astrocytes,whichsurroundbraincapillarieswiththeirendfeet,expresshistamineH1receptors(H1Rs)andH2Rs.HistaminergicandotherneuronswithterminalsaroundtheastrocyteendfeetcontainpresynapticH3Rs.CirculatingactivatedTlymphocytesexpressatleastH1Rs,andpossiblyalsoH2RsandH4Rs.Mastcells,whichexpressH1Rs,H2RsandH4Rs197,arefoundonlyinlimitedperivascularareasoftheratbrain(medianeminenceandthalamus)andarepotentiallyimportantinthehumanbrainandapossiblesourceofH4Rs.85乙酰膽堿和其他神經(jīng)遞質(zhì)第85頁SectionII:nitricoxideRobertFFurchgott,born1916Dept.ofPharmacology,SUNYHealthScienceCenterNewYorkLouisJIgnarro,born1941Dept.ofMolecularandMedicalPharmacologyUCLASchoolofMedicineLosAngelesFeridMurad,born1936Dept.ofIntegrativeBiologyPharmacologyandPhysiology,UniversityofTexasMedicalSchool,HoustondemonstratedthattherelaxationofbloodvesselsdescribedbyFurchgottwasduetoasubstanceproducedintheendothelium,whichhisgroupcalledendothelium-derivedrelaxingfactor(EDRF).In1987,IgnarrodemonstratedthatEDRFwasnitricoxide.86FurchgottandZawadzkishowedthattherelaxationofbloodvesselsdependedonanintactendothelium.showedthatnitroglycerinecausedbloodvesselstorelax,andthatthiswascausedbythereleaseofnitricoxidegas乙酰膽堿和其他神經(jīng)遞質(zhì)第86頁1.Biosynthesisandenzyme底物：L-精氨酸,

O2,NADPH產(chǎn)物：胍氨酸，NO酶：nitricoxidesynthase,NOS.NO合酶NO是極不穩(wěn)定脂溶性小分子，可快速擴散Whenexposedtooxygen,NOisconvertedintoNO2.2NO+O2→2NO2Inwater,NOreactwithoxygenandwatertoformHNO2.4NO+O2+2H2O→4HNO2血液中血紅蛋白是NO主要去除劑（scavenger），也是NO儲存和運輸工具87乙酰膽堿和其他神經(jīng)遞質(zhì)第87頁NameGene(s)DescriptionNeuronalNOS(nNOSorNOS1)NOS1ProducesNOinneuronaltissueinboththecentralandperipheralnervoussystem.NeuronalNOSalsoperformsaroleincellcommunicationandisassociatedwithplasmamembranes.InducibleNOS(iNOSorNOS2)NOS2A,NOS2B,NOS2CCanbefoundintheimmunesystembutisalsofoundinthebrainandcardiovascularsystem.EndothelialNOS(eNOSorNOS3orConstitutive/cNOS)mNOS

NOS3GeneratesNOinbloodvesselsandisinvolvedwithregulatingvascularfunction.AconstitutiveCa2+dependentNOSprovidesabasalreleaseofNO.eNOSisassociatedwithplasmamembranessurroundingcells.?88nNOS,eNOS是Ca2+-鈣調(diào)蛋白依賴性酶，為基本型

cNOS(constitutiveNOS)iNOS不依賴Ca2+-鈣調(diào)蛋白乙酰膽堿和其他神經(jīng)遞質(zhì)第88頁2.Cellactions無儲存囊泡擴散傳遞作用機制：1.激活鳥苷酸環(huán)化酶（guanylylcyclase,GC）2.修飾蛋白質(zhì)含鐵輔基，巰基，和芳香族氨基酸—參加炎癥和細胞損傷等病理過程第二信使激活蛋白激酶cGMP-dependentproteinkinase(PKG)additionalsecondmessengersystemscAMP-dependentkinasePKA89乙酰膽堿和其他神經(jīng)遞質(zhì)第89頁注意：它能夠擴散到其它細胞90效應：促進突觸功效，促進LTP乙酰膽堿和其他神經(jīng)遞質(zhì)第90頁3.FunctionsofNOinCNS（1）Modulationofneurotransmissionexertslong-lastingeffectsthroughregulationoftranscriptionfactorsandmodulationofgeneexpression（2）Leaningandmemory:

modulationofsynapticactivity,neuralplasticity，LTPandmemoryfunctions.（3）RegulationofneuronalsurvivalanddifferentiationNOdonors含有促進記憶。調(diào)整LTP，LTDNOdonorsareinuseinclinicalmanagementofcardiovasculardiseases.AmongNOdonors,molsidomine(脈導敏)hasahighbioavailability,along-lastingdurationofaction,likelycrossesthebloodbrainbarrier(BBB)91乙酰膽堿和其他神經(jīng)遞質(zhì)第91頁92亞硝基化92乙酰膽堿和其他神經(jīng)遞質(zhì)第92頁NO在神經(jīng)系統(tǒng)主要作用機制QuestionWithlowconcentrationsNOisneuroprotectiveandmediatephysiologicalsignaling(e.g.,neurotransmissionorvasodilatation),whereashigherconcentrationsmediateimmune/inflammatoryactions