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Abstract:
We have previously demonstrated that human subjects who abuse
cocaine showed increases in regional cerebral metabolic rates for
glucose (rCMRglc) using positron emission tomography (PET) when
exposed to cocaine-related stimuli. Furthermore, self-reports of
cocaine craving during cue exposure was significantly correlated
with increases in rCMRglc in the amygdala, prefrontal cortex and
cerebellum. We have now replicated these findings using our new,
higher-resolution Siemens HR Exact+ tomograph. Using the same
protocol as in the previous study, subjects participated in two
experimental sessions, a week apart, during which self-report and
PET measurements were collected. Subjects were exposed to a
videotape and paraphernalia related either to arts and crafts or to
cocaine use. Initial inspection of the data from the first 4
cocaine-abusing subjects revealed the same general pattern of
activation seen in the previous study. Specifically, subjects
showed increased rCMRglc in frontal, occipital, and temporal lobe
structures during exposure to drug-related cues that elicited
cocaine craving. In addition, the high resolution of the new
scanner allowed measurement of rCMRglc in areas such as the nucleus
accumbens and basal forebrain (extended amygdala) which were not
reliably visualized previously. A comparison of a pixel-by-pixel
analysis with the region of interest (ROI) analysis used in our
previous study largely yielded concordant results. (The NIDA Brain
Imaging Center is supported in part by the Office of National Drug
Control Policy.)
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