In the study, which is reported in the Nov.21 online edition of the Proceedings of the National Academy of Sciences, researchers used functional magnetic resonance imaging (fMRI) to detect an increase in blood flow to the prefrontal cortex in individuals subjected to stress. Further, the increase remained even when the stressor was removed, suggesting the effects of stress are more persistent than once thought.
Whereas most previous fMRI studies have relied on indirect measures of cerebral blood flow, the Penn team, led by John A. Detre, measured blood flow directly, using a technique called arterial spin labeling. The technique is non-invasive, relying on magnetically "tagging" the water molecules in subjects' blood.
This research is supported by the National Science Foundation, the National Institutes of Health, and the U.S. Air Force.
For a complete story, see the University of Pennsylvania release.
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