Cigarette smoking addiction, mechanism

On the right-hand side, we can see that the mechanism of addiction to cigarette smoking combines two chemical events (i) nicotine enhances dopanune release, and (ii) another molecule in the cigarette smoke, presumably ammonia (NH3 see blue spheres in Figure 1.4) intensifies the release of dopamine, while other additives block the enzyme MAOb- These events enhance the action of dopamine, which leads to the sensation of pleasure, alertness, and satisfaction, and eventually to addiction (recall the movie The Insider with Russell Crowe). Indeed, in the basis of human behavior, there lies an enticing simplicity of chemical origins. 

Abstract For more than a half century, tobacco manufacturers have conducted sophisticated internal research to evaluate nicotine delivery, and modified their products to ensure availability of nicotine to smokers and to optimize its effects. Tobacco has proven to be a particularly effective vehicle for nicotine, enabling manipulation of smoke chemistry and of mechanisms of delivery, and providing sensory cues that critically inform patterns of smoking behavior as well as reinforce the impact of nicotine. A range of physical and chemical product design changes provide precise control over the quantity, form, and perception of nicotine dose, and support compensatory behavior, which is driven by the smoker s addiction to nicotine. Cigarette... 

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