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Dopamine's role in inhibitory control is well recognized and its disruption may contribute to behavioral disorders of discontrol such as obesity. However, the mechanism by which impaired dopamine neurotransmission interferes with inhibitory control is poorly understood. We had previously documented a reduction in dopamine D2 receptors in morbidly obese(More)
The drive for food is one of the most powerful of human and animal behaviors. Dopamine, a neurotransmitter involved with motivation and reward, its believed to regulate food intake in laboratory animals by modulating its rewarding effects through the nucleus accumbens (NA). Here we assess the involvement of dopamine in "nonhedonic" food motivation in(More)
Methylphenidate hydrochloride (MP) is an effective treatment for attention-deficit/hyperactivity disorder (ADHD), a common neurobehavioral disorder of childhood onset characterized by inattention, hyperactivity, and distractibility. Methylphenidate hydrochloride blocks the dopamine transporters (DAT), the main mechanism for removing dopamine (DA) from the(More)
We had shown that striatal DA D2 receptors levels predicted the reinforcing responses to the psychostimulant drug methylphenidate in nondrug-abusing subjects. Here, we assessed the replicability of this finding. We measured D2 receptors with PET and [(11)C]raclopride (twice to determine stability) in seven nondrug-abusing subjects to assess if they(More)
Methylphenidate (Ritalin) is an effective drug in the treatment of attention deficit hyperactivity disorder. However, the doses required therapeutically vary significantly between subjects and it is not understood what determines these differences. Since methylphenidate's therapeutic effects are in part due to increases in extracellular DA secondary to(More)
[(11)C]P943 is a new radioligand recently developed to image and quantify serotonin 5-Hydroxytryptamine (5-HT(1B)) receptors with positron emission tomography (PET). The purpose of this study was to evaluate [(11)C]P943 for this application in humans, and to determine the most suitable quantification method. Positron emission tomography data and arterial(More)
Tourette syndrome (TS) is characterized by tics, sensorimotor gating deficiencies, and abnormalities of cortico-basal ganglia circuits. A mutation in histidine decarboxylase (Hdc), the key enzyme for the biosynthesis of histamine (HA), has been implicated as a rare genetic cause. Hdc knockout mice exhibited potentiated tic-like stereotypies, recapitulating(More)
Drugs of abuse are rewarding to addicted and nonaddicted subjects, but they trigger craving and compulsive intake only in addicted subjects. Here, we used positron emission tomography (PET) and [18F] deoxyglucose to compare the brain metabolic responses (marker of brain function) of cocaine-addicted subjects (n = 21) and controls (n = 15) to identify brain(More)
The reinforcing effects of drugs of abuse result from the complex interaction between pharmacological effects and conditioned responses. Here we evaluate how expectation affects the response to the stimulant drug methylphenidate in 25 cocaine abusers. The effects of methylphenidate (0.5 mg/kg, i.v.) on brain glucose metabolism (measured by(More)
OBJECTIVE Eating behavior in humans is influenced by variables other than just hunger-satiety including cognitive restraint, emotional distress, and sensitivity to food stimuli. We investigate the role of dopamine (DA), a neurotransmitter involved with food motivation, in these variables. METHODS We used the Dutch Eating Behavior Questionnaire (DEBQ) to(More)