Action PotentialsNeuronsMembrane PotentialsMembrane Potential, MitochondrialCell MembraneMembranesIntracellular MembranesElectrophysiologyCalciumPotassiumMembrane LipidsPatch-Clamp TechniquesElectric StimulationTetrodotoxinSodiumElectric ConductivityPotassium ChannelsMembranes, ArtificialGuinea PigsCell Membrane PermeabilityTime FactorsIon ChannelsCells, CulturedSodium ChannelsMitochondriaMicroelectrodesRats, Sprague-DawleyAxonsErythrocyte MembraneSynaptic TransmissionMembrane FluiditySynapsesNeural ConductionDendritesPotassium Channel BlockersHippocampus4-AminopyridineTetraethylammonium CompoundsHeartRats, WistarIon Channel GatingVentricular FunctionModels, BiologicalChloridesModels, NeurologicalCalcium ChannelsKineticsTetraethylammoniumFluorescent DyesBasement MembraneHeart Conduction SystemMitochondrial MembranesCell LineHydrogen-Ion ConcentrationDose-Response Relationship, DrugRabbitsValinomycinPyramidal CellsAdenosine TriphosphateAnimals, NewbornNeuronal PlasticityCalcium SignalingPotassium Channels, Voltage-GatedPurkinje FibersDogsPapillary MusclesEvoked PotentialsHeart VentriclesExcitatory Postsynaptic PotentialsBariumMembrane Transport ProteinsNerve Tissue ProteinsMotor NeuronsSodium Channel BlockersBrainCerebral CortexMyocytes, CardiacNeurons, AfferentCalcium Channel BlockersMicroscopy, ElectronCesiumSynaptic MembranesProtein TransportInterneuronsMyocardiumMembrane GlycoproteinsMutationBiological Transport, ActiveAnuraSignal TransductionApoptosisCalcium Channels, L-TypeNeural InhibitionMicroscopy, ConfocalCatsMusclesOuabainCarrier ProteinsLipid BilayersMicroscopy, Fluorescence