DiffusionIontophoresisDiffusion Magnetic Resonance ImagingDiffusion Tensor ImagingAnisotropyExtracellular SpaceNerve Fibers, MyelinatedElectroosmosisBrainSkin AbsorptionAdministration, CutaneousRats, HairlessDiffusion Chambers, CultureAcetylcholineNeuronsTime FactorsNailsModels, BiologicalMicroelectrodesMembrane PotentialsStrychnineScleraPermeabilityMannitolCatsDrug Delivery SystemsElectrophysiologyBicucullinePotassiumComputer SimulationAction PotentialsAlgorithmsCalciumBiological TransportSkinIon ExchangeFacilitated DiffusionElectric StimulationRats, Sprague-DawleyBufoteninRana pipiensLysergic Acid DiethylamideKineticsCell Membrane PermeabilityMicroscopy, ElectronAminobutyratesElectric ConductivitySodiumReproducibility of ResultsSynapsesgamma-Aminobutyric AcidGlutamatesImage Processing, Computer-AssistedCell MembraneNeural InhibitionGlutamic AcidSynaptic TransmissionMolluscaParasympathomimeticsRabbitsElectrodesInferior ColliculiComputer SystemsChloridesHydrogen-Ion ConcentrationFluorescent DyesTubocurarineTriazenesPhotobleachingExtracellular FluidRats, WistarSensitivity and SpecificityInulinVestibular NucleiMicroscopy, FluorescenceGlycineMagnetic Resonance ImagingTetraethylammoniumEvoked PotentialsMusclesMathematicsModels, TheoreticalNeuromuscular JunctionSynaptic MembranesHippocampusWaterSilverGangliaImage Interpretation, Computer-AssistedSwineDextransAdministration, TopicalCerebral CortexReceptors, CholinergicLanthanumDose-Response Relationship, DrugCells, CulturedThalamusImaging, Three-DimensionalSucrose