Szabolcs Lehel

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Overweight and obesity is a health threat of increasing concern and understanding the neurobiology behind obesity is instrumental to the development of effective treatment regimes. Serotonergic neurotransmission is critically involved in eating behaviour; cerebral level of serotonin (5-HT) in animal models is inversely related to food intake and body weight(More)
BACKGROUND A polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) has been associated with seasonality both in patients with seasonal affective disorder and in the general population. METHOD We used in vivo molecular imaging to measure cerebral serotonin transporter (5-HTT) binding in 57 healthy Scandinavians and related the(More)
The effects of vinpocetine (Cavinton) on the cerebral glucose metabolism of chronic stroke patients are studied with positron emission tomography. The regional and global cerebral metabolic rates of glucose (CMRglu) and the kinetic constants related to them are quantified before and after single-dose intravenous vinpocetine treatment. These measurements are(More)
The 5-HT4 receptor may play a role in memory and learning and 5-HT4 receptor activation has been suggested to modulate acetylcholine release and to reduce amyloid-β (Aβ) accumulation. The aim of this study was for the first time to investigate the in vivo cerebral 5-HT4 receptor binding in early Alzheimer disease (AD) patients in relation to cortical Aβ(More)
Positron emission tomography (PET) imaging of serotonin 2A (5-HT2A) receptors with agonist tracers holds promise for the selective labelling of 5-HT2A receptors in their high-affinity state. We have previously validated [11C]Cimbi-5 and found that it is a 5-HT2A receptor agonist PET tracer. In an attempt to further optimize the target-to-background binding(More)
[(11)C]Cimbi-36 was recently developed as a selective serotonin 2A (5-HT(2A)) receptor agonist radioligand for positron emission tomography (PET) brain imaging. Such an agonist PET radioligand may provide a novel, and more functional, measure of the serotonergic system and agonist binding is more likely than antagonist binding to reflect 5-HT levels in(More)
Identification of a biomarker that can inform on extracellular serotonin (5-HT) levels in the brains of living humans would enable greater understanding of the way brain circuits are modulated by serotonergic neurotransmission. Substantial evidence from studies in animals and humans indicates an inverse relationship between central 5-HT tonus and 5-HT type(More)
The pharmacological effects of the neuroprotective drug vinpocetine, administered intravenously in a 14-day long treatment regime, on the cerebral blood flow and cerebral glucose metabolism in chronic ischemic stroke patients (n=13) were studied with positron emission tomography in a double-blind design. The regional and global cerebral metabolic rates of(More)
UNLABELLED Small-molecule α(7) nicotinic acetylcholine receptor (α(7)nAChR) agonists are currently validated for use as treatment for cognitive disturbances in schizophrenia and in Alzheimer disease. A suitable radiolabeled α(7)nAChR PET tracer would be important for in vivo quantification of α(7)nAChR binding in humans and to measure α(7)nAChR occupancy of(More)
UNLABELLED The serotonin (5-hydroxytryptamine [5-ΗΤ]) 7 receptor (5-HT7R) is the most recently discovered 5-HT receptor, and its physiologic and possible pathophysiologic roles are not fully elucidated. So far, no suitable 5-HT7R PET radioligand is available, thus limiting the investigation of this receptor in the living brain. Here, we present the(More)