NicotineNicotinic AgonistsTobacco Use DisorderGanglionic StimulantsReceptors, NicotinicMecamylamineCotinineNicotinic AntagonistsChewing GumSubstance Withdrawal SyndromeTobacco Use Cessation ProductsSmoking CessationSmokingAdministration, CutaneousDihydro-beta-ErythroidineTarsSelf Administrationalpha7 Nicotinic Acetylcholine ReceptorDose-Response Relationship, DrugAzocinesRats, Sprague-DawleyConditioning, OperantAconitineRewardQuinolizinesTobacco, SmokelessTobacco ProductsBehavior, AnimalTobaccoTime FactorsReinforcement (Psychology)AnabasineBicyclo Compounds, HeterocyclicBrainAnalysis of VarianceCarbon MonoxideSelf StimulationDopamineHexamethoniumBenzazepinesTobacco Smoke PollutionBungarotoxinsMotor ActivityHexamethonium CompoundsQuinoxalinesVentral Tegmental AreaNitrosaminesMice, Inbred C57BLPyridinesSmokePrenatal Exposure Delayed EffectsNucleus AccumbensDisease Models, AnimalDrug Interactions