Pain ThresholdPainPain MeasurementPhysical StimulationHot TemperatureAnalgesiaPain PerceptionHyperalgesiaAnalgesicsAnalgesics, OpioidPain ManagementEar, ExternalDiffuse Noxious Inhibitory ControlNociceptorsCold TemperatureAnalgesics, Non-NarcoticSensory ThresholdsPressureAlfentanilWristTranscutaneous Electric Nerve StimulationPentazocineFibromyalgiaElectric StimulationCapsaicinMorphineChronic PainElectric Stimulation TherapyCatechol O-MethyltransferaseNociceptionPain, PostoperativeDouble-Blind MethodLow Back PainBack PainSpinal CordTime FactorsSkinCross-Over StudiesSex CharacteristicsAbdominal PainRats, Sprague-DawleyPain, IntractableNeck PainPosterior Horn CellsNeurons, AfferentReflexInjections, SpinalMustard PlantReaction TimePelvic PainBehavior, AnimalTouchFacial PainTRPV Cation ChannelsNeuronsEscape ReactionPhotic StimulationAfferent PathwaysIsofluraneAcute PainAnesthetics, InhalationPain, ReferredFormaldehydePropofolReticular FormationMonitoring, IntraoperativeThermosensingElectroencephalographyFentanylNaloxoneAnesthesia, InhalationTetanyDose-Response Relationship, DrugAnesthesiaTailGanglia, SpinalAction PotentialsSensory Receptor CellsMechanoreceptorsAnesthetics, IntravenousShoulder PainModels, BiologicalCentral Nervous System SensitizationMusculoskeletal PainBrain MappingHalothaneElectrophysiologyAvoidance LearningEvoked PotentialsElectroshockNerve Fibers, UnmyelinatedTrigeminal NerveConsciousnessMethyl EthersDermatologic Surgical ProceduresNarcoticsMovementGeneralization, StimulusAnalysis of VarianceAcoustic Stimulation