But when men and women have nicotine in their bodies, these brain activity differences practically disappear. Among both smokers and non-smokers on nicotine, during aggressive moments such as impulsive or hostile acts, there are virtually no differences in brain activity between the sexes -- illustrating how nicotine can impact brain function. Results of the study, conducted by Brain Imaging Center researchers supported by the UCI Transdisciplinary Tobacco Use Research Center, are published in the online edition of the International Journal of Neuropsychopharmacology, and will be available in print next month.

The researchers found during behavioral and brain-imaging tests on hostility and impulsive reaction that brain-metabolism activity -- which indicates when neurons are working -- was much higher in many brain areas of women than men. But when the test subjects were given nicotine, metabolic activity significantly declined in the women and slightly increased in men -- the original differences all but disappeared.

According to Dr. Steven Potkin, who along with neuroanatomist James Fallon led the study, these results shed light on two issues. First, brain activity areas involved in choice, attention, short-term memory, planning, mood, emotion and language are different in men and women -- differences exaggerated during moments of hostility or impulsiveness. In addition, the study provides new evidence that men's and women's brains respond differently to the same stimuli -- a result sure to fuel the ongoing debate over fundamental variations in brain function based on gender. Since these differences are present even in non-smokers, they appear to be inherent differences in brain me
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Contact: Louri Groves
lgroves@uci.edu
949-824-9307
University of California - Irvine
17-Feb-2005