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Genetic factors, externalizing personality traits such as impulsivity, and brain processing of salient stimuli all can affect individual risk for alcoholism. One of very few confirmed genetic association findings differentiating alcoholics from non-alcoholics is with variants in the inhibitory γ-amino butyric acid α2 receptor subunit (GABRA2) gene. Here we(More)
The hypothesis for this research was that regional cerebral blood flow (rCBF) would increase following nasal nicotine administration to overnight abstinent tobacco smokers in relationship to the known brain distribution of nicotinic cholinergic receptors (nAChRs). Nine male and nine female healthy adult smokers were studied. They abstained overnight from(More)
OBJECTIVE Both age and gender are being increasingly recognized as important factors influencing CNS structure and function. However, there are relatively few data on actual neurochemical differences between the sexes in human subjects or on their interaction with age. One of the central neurotransmitter systems for which sex differences have been suggested(More)
Eleven healthy tobacco smoking adult male volunteers of mixed race were tobacco abstinent overnight for this study. In each subject, positron emission tomographic images of regional cerebral metabolism of glucose with [18F]fluorodeoxyglucose were obtained in two conditions in the morning on different days: about 3min after approximately 1-2mg of nasal(More)
BACKGROUND Most people agree that dependence to tobacco is mediated by the effects of nicotine on the central nervous system, albeit the neural pathways involved are not clearly delineated. We investigated the effect of nasal nicotine spray on regional cerebral blood flow (rCBF) in a sample of habitual smokers, with H2 15O and positron emission tomography(More)
Measurements of cerebral metabolism in patients with Alzheimer's disease (AD) using PET are artifactually depressed due to partial volume averaging of brain tissue activity with enlarged CSF spaces. To investigate the effects of correction for the expansion of CSF spaces on regional metabolic measures, as well as the correlations between neuropsychological(More)
OBJECTIVE Increases in adrenergic activity are associated with stress, anxiety, and other psychiatric, neurological, and medical disorders. To improve understanding of normal CNS adrenergic function, CBF responses to adrenergic stimulation were determined. METHODS Using PET, the CBF changes after intravenous yohimbine, an alpha2-adrenoreceptor antagonist(More)
The regulation of central mu-opioid receptors in women during the menstrual cycle was explored with positron emission tomography and the selective radiotracer [11C]carfentanil. Ten healthy women were studied twice, during their follicular and luteal phases. Plasma concentrations of estradiol, progesterone, testosterone, and beta-endorphin were determined(More)
The involvement of opioid neurotransmitter systems in seizure mechanisms is well documented. In previous positron emission tomography (PET) studies in patients with unilateral temporal lobe epilepsy, we have found evidence for differential regulation of the opioid-receptor subtypes. The present study extends our previous observations to delta-opioid(More)
PURPOSE Our goal was to evaluate the influence of spatially heterogeneous background activity on "hot object" quantitation in brain emission CT. METHOD We studied the effects of spatially heterogeneous background activity on hot object quantitative recovery in simulations of both spheres and realistic brain distributions (utilizing human MRI data). (More)