Results of a new imaging study, supported in part by the National Institute on Drug Abuse (NIDA), National Institutes of Health, show that the nicotine received in just a few puffs of a cigarette can exert a force powerful enough to drive an individual to continue smoking. Researchers found that the amount of nicotine contained in just one puff of a cigarette can occupy about 30 percent of the brain’s most common type of nicotine receptors, while three puffs of a cigarette can occupy about 70 percent of these receptors. When nearly all of the receptors are occupied (as a result of smoking at least 2 and one-half cigarettes), the smoker becomes satiated, or satisfied, for a time. Soon, however, this level of satiation wears off, driving the smoker to continue smoking throughout the day to satisfy cigarette cravings.
