Section B. SynapsesIntroductionof SynapsesEPSP and IPSPSynaptic Integration and Synaptic StrengthNeurotransmitters and NeuromodulatorsActionpotential6SResponseof cell2011PearsonEducation,inc
Section B. Synapses • Introduction of Synapses • EPSP and IPSP • Synaptic Integration and Synaptic Strength • Neurotransmitters and Neuromodulators
Introduction of Synapses·A structurepermitting a neuron to pass an electricalor chemicalsignalto another.Axon/DendritepresynapticSpinesynapseDendriteShaftsynapseExtracellularspacepostsynapticAxonCell body/Axon/DendriteAxodendriticAxosomaticAxo-axonicsynapsessynapsessynapse
Introduction of Synapses • Axon/Dendrite • Extracellular space • Cell body /Axon/Dendrite presynaptic postsynaptic • A structure permitting a neuron to pass an electrical or chemical signal to another
Types of Synapsespresynapticpostsynapticchemical+ResponselectricalactionpotentialsignalChemicalsynapsesElectricalsynapses(Gapjunctions)electricalelectrical
Types of Synapses
Functional Anatomy of Chemical SynapsesPresynapticneuron·Chemical Synapse-PresynapticmembraneTerminalsynapticvesicles-neurotransmitter- Synaptic cleftPostsynapticVesicleneuron10to20nmspace880CMHKSEMitochondrion-Postsynapticmembrane8.8receptors,hydrolyticenzymes福ReleasedneurotransmittermoleculesSynapticcleftPostsynapticmembranecontaining receptors
Functional Anatomy of Chemical Synapses • Chemical Synapse -Presynaptic membrane synaptic vesicles- neurotransmitter - Synaptic cleft 10 to 20nm space - Postsynaptic membrane receptors, hydrolytic enzymes
Release of Neurotransmitter(a)OActionpotential?Voltage-gated Ca2reachesterminalchannelsopenVoltage-gated-AxonterminalCa2channelCa2-Synapticvesicles-Active③CalciumenterszoneaxonterminalNeurotransmitterisreleasedandCa2diffuses into theV-SNAREcleft.'t-SNARENeurotransmitterNeurotransmitterbindsremovedfromtopostsynapticreceptorssynaptic cleft·Direct-ReuptakePostsynaptic cell·Indirect(Gprotein)·Diffuse away·Enzymaticallytransformedforreuse
Release of Neurotransmitter •Direct •Indirect (G protein) •Reuptake •Diffuse away •Enzymatically transformed for reuse •v-SNARE •t-SNARE