Administration, OralRats, Sprague-DawleyInjections, IntravenousDose-Response Relationship, DrugInjections, IntraperitonealDrug Administration ScheduleDrug Administration RoutesDisease Models, AnimalTime FactorsMice, Inbred C57BLRats, WistarUnited States Food and Drug AdministrationInjections, SubcutaneousInjections, IntraventricularMice, Inbred BALB CAdministration, IntravenousMicrodialysisAdministration, IntranasalLiverBehavior, AnimalGenetic TherapyAdministration, TopicalInjections, IntramuscularDrug InteractionsMorphineTissue DistributionInjectionsAnalgesicsInfusions, IntravenousGenetic VectorsBrainRecombinant ProteinsInjections, SpinalHalf-LifeNaloxoneAdministration, RectalRats, Inbred StrainsMotor ActivityBiological Availability8-Hydroxy-2-(di-n-propylamino)tetralinAnalysis of VarianceDopamineAdenoviridaeBlood PressureAnalgesics, OpioidDogsDopamine AntagonistsDrug Delivery SystemsMice, NudeBenzazepinesNeoplasm TransplantationMice, KnockoutPiperidinesNarcotic AntagonistsRabbitsArea Under CurveRNA, MessengerRandom AllocationSerotonin AntagonistsKidneyDrug ToleranceTreatment OutcomeEnzyme InhibitorsApomorphineMicroinjectionsLungCorpus StriatumSelf AdministrationProdrugsSerotonin Receptor AgonistsDrug Evaluation, PreclinicalRats, Long-EvansGene Transfer TechniquesRats, Inbred F344Mice, Inbred ICRPainBody WeightAdministration, CutaneousAntineoplastic AgentsXenograft Model Antitumor AssaysPain MeasurementImmunohistochemistryNucleus AccumbensChromatography, High Pressure LiquidMice, Inbred StrainsNeuronsNeuroprotective AgentsNeoplasms, ExperimentalDrug SynergismPiperazinesCocaineCells, CulturedCell Line, TumorHyperalgesiaSpleenDouble-Blind MethodSerotoninModels, AnimalNanoparticlesEthanol