James R. Brasic

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OBJECTIVE Dopaminergic abnormalities in frontal-subcortical circuits have been hypothesized as the underlying pathophysiologic mechanism in Tourette's syndrome. The objective of this study was to test the hypothesis that presynaptic dopamine release from the striatum is abnormal in adults with Tourette's syndrome. METHOD Seven adults with Tourette's(More)
Several studies have examined the link between the cannabinoid CB1 receptor and several neuropsychiatric illnesses, including schizophrenia. As such, there is a need for in vivo imaging tracers so that the relationship between CB1 and schizophrenia (SZ) can be further studied. In this paper, we present our first human studies in both healthy control(More)
In quantitative dynamic PET studies, graphical analysis methods including the Gjedde-Patlak plot, the Logan plot, and the relative equilibrium-based graphical plot (RE plot) (Zhou Y., Ye W., Brasić J.R., Crabb A.H., Hilton J., Wong D.F. 2009b. A consistent and efficient graphical analysis method to improve the quantification of reversible tracer binding in(More)
UNLABELLED We evaluated (-)-2-(6-[(18)F]fluoro-2,3'-bipyridin-5'-yl)-7-methyl-7-aza-bicyclo[2.2.1]heptane ((18)F-AZAN), a novel radiotracer that binds to α4β2 nicotinic acetylcholine receptors (α4β2-nAChRs) and shows high specific binding and rapid and reversible kinetics in the baboon and human brain. METHODS We tested safety tolerability and test-retest(More)
RATIONALE Although it is well established that acute benzodiazepine administration impairs episodic memory encoding, little is known about the neuroanatomical substrates of this effect. OBJECTIVE The objective was to examine the acute dose effects of the benzodiazepine hypnotic triazolam on brain activity during episodic memory encoding. METHODS After(More)
PURPOSE Using the α7-nAChR radiotracer, [(18)F]ASEM, we present the first successful human positron emission tomography (PET) studies. Rodent occupancy with three clinically employed α7-nAChR drugs confirms the specificity of the radiotracer. PROCEDURES Five healthy male subjects were imaged for 90 min following IV [(18)F]ASEM. Two subjects were scanned(More)
Childhood exposure to severe or chronic trauma is an important risk factor for the later development of adult mental health problems, such as substance abuse. Even in nonclinical samples of healthy adults, persons with a history of significant childhood adversity seem to experience greater psychological distress than those without this history. Evidence(More)
PURPOSE Disrupted-in-schizophrenia-1 (DISC1) is a promising genetic susceptibility factor for major psychiatric conditions, such as schizophrenia. We hypothesized that the mutant DISC1 alters the homeostasis of multi-receptor interactions between dopaminergic [dopamine 2/3 (D(2/3)R)], glutamatergic [metabotropic glutamate 5 (mGluR5)], cannabinoid 1(More)
The rewarding effects of nicotine are associated with activation of nicotine receptors. However, there is increasing evidence that the endogenous opioid system is involved in nicotine's rewarding effects. We employed PET imaging with [11C]carfentanil to test the hypotheses that acute cigarette smoking increases release of endogenous opioids in the human(More)