Nicotine: The Physiologic Mechanism of Tobacco Dependence
Credit: Jane Hurd, Donna DeSmet, Jason Guerrero, Donald Tolentino

With every drag a smoker takes, trillions of nicotine molecules rush from the lungs to the bloodstream and into the brain, where they bind to α4β2 nicotinic acetylcholine receptors and stimulate the release of pleasure-inducing dopamine. But as nicotine is eliminated, dopamine levels fall, and smokers begin to crave another dose. Over time, the brain becomes dependent on the drug, and the result is an addiction that claims 4 million lives a year from emphysema, lung cancer, heart disease, and other smoking-related diseases. That is the message of this video, created by art director Donna DeSmet, animator Jason Guerrero, and their team at New York City–based Hurd Studios, a scientific visualization company specializing in "cutting-edge science with educational aspects," according to President Jane Hurd.