Researchers at the Abramson Cancer Center of the University of Pennsylvania used a novel method of measuring brain blood flow developed at the university that shows that abstinence from nicotine produces brain activation patterns that relate to urges to smoke.

Senior author Caryn Lerman, colleagues Dr. John Detre and Ze Wang said cigarette cravings are a hallmark of drug dependence, including nicotine dependence.

"There have been several brain imaging studies showing how subjects respond to visual, smoking-related cues, such as a picture of a cigarette or of someone smoking," Lerman said in a statement. "However, less is known about the neural basis of urges that arise naturally as a result of nicotine deprivation."

Each participant was scanned to measure the cerebral blood flow, during a resting state on two separate occasions: participants smoked a cigarette within an hour of the one scan, and abstained from smoking overnight for the other scan.

The findings, published in the The Journal of Neuroscience, indicate that abstinence-induced, unprovoked cravings to smoke are associated with increased activation in brain regions important in attention, behavioral control, memory, and reward.