Kurt Kletter

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BACKGROUND Results from studies in serotonin-1A (5-HT1A) knockout mice and previous positron emission tomography (PET) studies in humans imply a role for 5-HT1A receptors in normal state anxiety as well as in certain anxiety disorders. The objective of this study was to investigate 5-HT1A receptor binding potential (BP) in social anxiety disorder (SAD). (More)
OBJECTIVES Various studies indicate that serotonin regulates impulsivity and the inhibitory control of aggression. Aggression is also known to be modified by sex hormones, which exert influence on serotonergic neurotransmission. The present study aimed to elucidate potential interactions between human aggression, the inhibitory serotonergic 5-HT(1A)(More)
PURPOSE AND METHODS Regional overexpression of the multidrug transporter P-glycoprotein (P-gp) in epileptic brain tissue may lower target site concentrations of antiepileptic drugs and thus contribute to pharmacoresistance in epilepsy. We used the P-gp substrate R-[(11)C]verapamil and positron emission tomography (PET) to test for differences in P-gp(More)
PURPOSE The higher prevalence rates of depression and anxiety disorders in women compared to men have been associated with sexual dimorphisms in the serotonergic system. The present positron emission tomography (PET) study investigated the influence of sex on the major inhibitory serotonergic receptor subtype, the serotonin-1A (5-HT(1A)) receptor. METHODS(More)
Receptor distribution patterns of neurotransmitters and distinct functional fields of the human brain appear to be tightly connected with respect to their topological allocation along the cerebral cortex. There is, however, considerable lack of human data directly demonstrating this association in vivo. Here, we assessed the relationship between the(More)
Dysregulation of the hypothalamic-pituitary-adrenocortical axis with deficient glucocorticoid feedback and alterations in the serotonergic system have been identified as biological correlates of mood disorders. Close examination of the interaction between these systems may offer insights into the pathophysiology of anxiety disorders and depression to(More)
OBJECTIVE Climate, in particular sunshine, influences mood and energy levels, creating a positive upswing of mood on bright, sunny days and negative downswing in cold, dark winter seasons. Higher serotonin transporter availability in healthy human subjects in times of lesser light exposure and lower serotonin levels have been shown in winter. METHODS We(More)
Serotonin modulates the activity of the hypothalamic-pituitary-adrenal (HPA) axis particularly via the serotonin-1A receptor (5-HT(1A)). Therefore, the rationale of this positron emission tomography (PET) study was to investigate the influence of the 5-HT(1A) receptor distribution in the human brain on plasma levels of dehydroepiandrosterone sulfate (DHEAS)(More)
We performed positron emission tomography using [carbonyl-(11)C]WAY-100635, a serotonin 1A (5-HT(1A)) receptor antagonist, in 13 patients with temporal lobe epilepsy (TLE) and in 13 controls. 5-HT(1A) receptor distribution mapping allowed correct lateralization of the epileptogenic temporal lobe in all patients. 5-HT(1A) receptor binding potential (BP(ND))(More)
PURPOSE The aim of this study was to assess the influence of age on the functional activity of the multidrug efflux transporter P-glycoprotein (P-gp) at the human blood-brain barrier. METHODS Seven young (mean age: 27 +/- 4 years) and six elderly (mean age: 69 +/- 9 years) healthy volunteers underwent dynamic (R)-[(11)C]verapamil (VPM) positron emission(More)