When smokers satisfy their urge for a cigarette, they dampen their mental resistance to addiction. Researchers at the University of Michigan at Ann Arbor imaged smokers' cerebral blood flow as they puffed on a cigarette after a night of nicotine abstinence. They also took images as the subjects smoked a low-nicotine cigarette. Comparing the two images removed signs of activity related to the nonnicotine aspects of smoking, leaving a map of pure nicotine stimulation. The drug intake increased blood flow in areas rich in nicotine receptors. But it also decreased blood flow in areas involved in memory formation and regions that normally moderate drug-seeking behavior.
This article was originally published with the title Where Addiction Lies.