PhotonsTomography, Emission-Computed, Single-PhotonMicroscopy, Fluorescence, MultiphotonLightSpectrometry, FluorescenceLasersEnergy TransferAction PotentialsPhantoms, ImagingNeural InhibitionFluorescenceFluorescent DyesElectric StimulationScattering, RadiationElementary ParticlesOptics and PhotonicsNeuronsPhotochemistryEquipment DesignMonte Carlo MethodRadiometryEquipment Failure AnalysisTime FactorsScintillation CountingSpectrum AnalysisElectronsChlorophyllComputer SimulationOptical ProcessesLuminescenceElectrophysiologySynaptic TransmissionQuantum TheoryLight-Harvesting Protein ComplexesCatsRadiation DosageExcitatory Postsynaptic PotentialsSynapsesSpectrum Analysis, RamanImage EnhancementOrganotechnetium CompoundsPhotosynthesisBiophysicsSemiconductorsParticle AcceleratorsPhotosynthetic Reaction Center Complex ProteinsLuminescent MeasurementsPhotosystem II Protein ComplexMicroscopy, FluorescenceMotor NeuronsInterneuronsAlgorithmsMembrane PotentialsRhodopsinImage Processing, Computer-AssistedRadiopharmaceuticalsTechnetium Tc 99m ExametazimeTomography, OpticalPhotochemical ProcessesModels, NeurologicalModels, TheoreticalThallium RadioisotopesRadiationSensitivity and SpecificityBiophysical PhenomenaTechnetiumTelluriumPhotobleachingDose-Response Relationship, RadiationPhotosystem I Protein ComplexReproducibility of ResultsInfrared RaysDiagnostic ImagingPatch-Clamp TechniquesImage Interpretation, Computer-AssistedSpectrophotometryTomography, Emission-ComputedOximesPhotoreceptor CellsInhibitory Postsynaptic PotentialsTransducersGABA AntagonistsRadio WavesMicroscopy, ConfocalRadiotherapy Planning, Computer-AssistedRelative Biological EffectivenessEvoked PotentialsNeurons, AfferentKineticsFluorescence PolarizationRadiotherapy, High-EnergyComputer-Aided DesignCadmium CompoundsFluorescence Resonance Energy TransferArtifactsRadiotherapy DosageModels, BiologicalSignal Processing, Computer-AssistedIodine RadioisotopesAfferent Pathways