NicotineNicotinic AgonistsTobacco Use DisorderGanglionic StimulantsReceptors, NicotinicSubstance Withdrawal SyndromeMecamylamineCotinineChewing GumNicotinic AntagonistsSmoking CessationSmokingTobacco Use Cessation ProductsAdministration, CutaneousAlcoholismDihydro-beta-ErythroidineSelf AdministrationTarsMorphine Dependencealpha7 Nicotinic Acetylcholine ReceptorDose-Response Relationship, DrugAzocinesRats, Sprague-DawleyKineticsTime FactorsConditioning, OperantTobacco ProductsSubstance-Related DisordersRewardAconitineTobacco, SmokelessQuinolizinesDrug ToleranceHydrogen-Ion ConcentrationBehavior, AnimalReinforcement (Psychology)Carbon MonoxideTobaccoBicyclo Compounds, HeterocyclicMarijuana AbuseHeroin DependenceOpioid-Related DisordersAnabasineDopamineTemperatureBrainSelf StimulationBenzazepinesAnalysis of VarianceMembrane PotentialsHexamethoniumNarcotic AntagonistsDiagnostic and Statistical Manual of Mental DisordersQuinoxalinesMotivationCalciumVentral Tegmental AreaTobacco Smoke PollutionBungarotoxinsMotor ActivityHexamethonium CompoundsPyridinesCocaine-Related DisordersNucleus AccumbensNitrosaminesTobacco Use CessationRats, WistarDrug InteractionsEthanolSmokeNeuronsElectrophysiologyReinforcement ScheduleModels, BiologicalAlkaloidsNaltrexoneCarboxyhemoglobin