NicotineNicotinic AgonistsTobacco Use DisorderGanglionic StimulantsReceptors, NicotinicMecamylamineCotinineNicotinic AntagonistsChewing GumSubstance Withdrawal SyndromeTobacco Use Cessation ProductsSmoking CessationSmokingAdministration, CutaneousDihydro-beta-ErythroidineSelf AdministrationTarsalpha7 Nicotinic Acetylcholine ReceptorRats, Sprague-DawleyAzocinesTime FactorsConditioning, OperantDose-Response Relationship, DrugAconitineDrug Administration ScheduleLethal Dose 50QuinolizinesAdministration, OralRadiation DosageTobacco, SmokelessBehavior, AnimalRewardTobacco ProductsDouble-Blind MethodTobaccoBicyclo Compounds, HeterocyclicReinforcement (Psychology)Drug InteractionsAnabasineAnalysis of VarianceDopamineBenzazepinesCarbon MonoxideSelf StimulationHexamethoniumInjections, IntravenousRats, WistarRadiometryPyridinesMotor ActivityBrainTreatment OutcomeHexamethonium CompoundsNitrosaminesQuinoxalinesTobacco Smoke PollutionBungarotoxinsVentral Tegmental AreaSmokeInfusions, IntravenousPrenatal Exposure Delayed EffectsDrug ToleranceNucleus AccumbensInfusion Pumps, ImplantableReinforcement ScheduleAlkaloids