ButyrylcholinesteraseCocaineHydrolysisCocaine-Related DisordersDopamine Uptake InhibitorsCrack CocaineSelf AdministrationConditioning, OperantNucleus AccumbensKineticsReinforcement (Psychology)Behavior, AddictiveAdenosine TriphosphateDrug-Seeking BehaviorBehavior, AnimalReinforcement ScheduleDose-Response Relationship, Drug