HyperalgesiaAnalgesiaAnalgesia, EpiduralAnalgesia, ObstetricalAnalgesia, Patient-ControlledPain MeasurementAnalgesics, OpioidPain ThresholdPainPain, PostoperativeAnalgesicsMorphineInjections, SpinalNociceptorsAnesthetics, LocalBupivacaineCarrageenanFentanylAcupuncture AnalgesiaRats, Sprague-DawleyPhysical StimulationCapsaicinHot TemperatureSpinal CordAnesthesia, EpiduralNeuralgiaFreund's AdjuvantMeperidineNerve BlockAnalgesics, Non-NarcoticDrug ToleranceLabor PainSufentanilGanglia, SpinalNaloxoneTRPV Cation ChannelsReceptors, Opioid, muPosterior Horn CellsKetamineLabor, ObstetricDouble-Blind MethodLidocaineAnesthesia, ObstetricalTouchAmidesNarcotic AntagonistsBehavior, AnimalNociceptionDose-Response Relationship, DrugOpioid PeptidesAnesthesia, SpinalSciatic NeuropathyTramadolReceptors, OpioidMustard PlantElectroacupunctureDisease Models, AnimalKetorolacCyclohexanecarboxylic AcidsHyperesthesiaPain ManagementSpinal NervesPiperidinesVisceral PainSciatic NerveInflammationSensory Receptor CellsCesarean SectionPostoperative Nausea and VomitingInterpleural AnalgesiaFootClonidinePain, ReferredAlfentanilMorphine DerivativesNociceptive PainNerve Fibers, UnmyelinatedAnesthetics, DissociativeSensory System AgentsAnesthesia, GeneralConscious SedationPeripheral Nervous System DiseasesAnti-Inflammatory Agents, Non-SteroidalRats, WistarLabor Stage, FirstEdemaHydromorphonePeriaqueductal GrayReceptors, Neurokinin-1HindlimbNeurons, AfferentDexmedetomidineSubstance PPlacebo EffectAnesthesia, CaudalPain, IntractableHypnotics and SedativesAnesthesia and AnalgesiaFormaldehydeTime Factors