Search results for "PAM"
showing 10 items of 1768 documents
Prediction error signal correlates with fluid intelligenceand dopamine synthesis across the lifespan
2011
IntroductionFluid intelligence expresses the capacity for interpretation of novel stimuli and flexible behavioral adaptation to such cues. Phasic dopamine firing closely matches a temporal difference prediction error (PE) signal important for learning and rapid behavioral adaptation. Both fluid intelligence and dopaminergic neurotransmission decline with age. So far, no study investigated the relationship between fluid IQ, PE signal and direct measures of dopaminergic neurotransmission. Here we used a multimodal imaging approach that combines positron emission tomography and functional magnetic resonance imaging.MethodsA group of healthy controls was investigated with both 6-[18F]FluoroDOPA…
Tropane-derived11C-labelled and18F-labelled DAT ligands
2013
Radiolabelling of cocaine-derived 3-phenyltropanes for dopamine transporter positron emission tomography with 18F and 11C is reviewed. Copyright © 2013 John Wiley & Sons, Ltd.
Determination of Drug Concentrations in Serum and Dopamine Receptor Occupancy in Brain for Optimal Antipsychotic Drug Therapy
2009
Evidence has been given that antipsychotic effects of dopamine receptor antagonists are associated with 60 and 80% striatal dopamine D2 and D3 receptor occupancy. Receptor occupancy correlates well with concentrations of the antipsychotic drugs in serum or plasma, much better than the dose. The latter is consistent with weak correlations between antipsychotic dose and serum concentrations and explained by the high interindividual variabilities in drug metabolism. Using positron emission tomography (PET) for in vivo determination of dopamine receptor occupancy in conjunction with drug concentration measurements “therapeutic windows” could be calculated for the atypical antipsychotic drugs am…
?-Carboline binding indicates the presence of benzodiazepine receptor subclasses in the bovine central nervous system
1982
Receptor binding studies were performed with tritiated propyl β-carboline-3-carboxylate ([3H]PrCC), tritiated ethyl β-carboline-3-carboxylate ([3H]ECC), and tritiated flunitrazepam ([3H]FNT) in membrane preparations from different regions of the bovine brain and retina. Specific binding in all regions investigated was associated with benzodiazepine receptor sites. However, not all benzodiazepine receptor sites. However, not all benzodiazepine receptors in the regions investigated as determined by the specific binding of tritiated flunitrazepam ([3H]FNT) are available for [3H]PrCC suggesting that specific [3H]PrCC binding labels only one subclass or subpopulation of the benzodiazepine recept…
Identification and Quantification of Dopamine Receptor 2 in Human Eutopic and Ectopic Endometrium: A Novel Molecular Target for Endometriosis Therapy1
2010
Previous studies in an experimental mouse model of endometriosis have shown that the dopamine agonist (DA) cabergoline (Cb2) reduces angiogenesis and endometriotic lesions, hypothetically binding to the dopamine receptor type-2 (DRD2). To date, this has not been described in human endometrium and/or endometriotic lesions. Thus, we aimed to investigate the presence of DRD2 in said tissues. Endometrium fragments were implanted in nude mice treated with different doses of Cb2. Polymerase chain reaction assays and immunohistochemistry were performed to analyze the gene and protein expressions (respectively) of DRD2, VEGF, and VEGF receptor-2 (KDR). In addition, lesions and endometrium from wome…
Effects of Different Anxiety Levels on the Behavioral Patternings Investigated through T-pattern Analysis in Wistar Rats Tested in the Hole-Board App…
2021
The Hole-Board is an ethologically based tool for investigating the anxiety-related behavior of rats following manipulation of the central anxiety level. The present paper aims to assess behavioral patterning following pharmacological manipulation of emotional assets in Wistar rats tested in this experimental apparatus. For this purpose, the behavior of three groups of rats injected with saline, diazepam or FG7142 was evaluated using conventional quantitative and multivariate Tpattern analyses. The results demonstrate that quantitative analyses of individual components of the behavior, disjointed from the comprehensive behavioral structure, are of narrow utility in the understanding of the …
Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.
1993
Abstract We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca2+-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca2+-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholi…
Binge eating and psychostimulant addiction.
2021
Many of the various factors, characteristics, and variables involved in the addictive process can determine an individual's vulnerability to develop drug addiction. Hedonic eating, based on pleasure rather than energy needs, modulates the same reward circuits, as do drugs of abuse. According to the last report of the World Health Organization, the worldwide obesity rate has more than doubled since 1980, reaching especially critical levels in children and young people, who are overexposed to high-fat, high-sugar, energy-dense foods. Over the past few decades, there has been an increase in the number of studies focused on how eating disorders can lead to the development of drug addiction and …
The influence of dopamine on hemodynamics, microcirculation and renal function in patients with hypnotic drug intoxication
1976
The effect of dopamine on hemodynamics (CO, AoPm, TPR, SV, SW, CVP, PAPm, PAEDP), microcirculation (MBF, PS-product) and renal function (VU, CKI, CNa, CK, Cosm, TcH2O) was studied in 8 patients with hypnotic drug poisoning. With increasing doses of dopamine, cardiac output and heart rate increased and the peripheral resistance decreased. An augmentation of stroke volume and left ventricular stroke work was observed in the low dose range only (200--400 mug/min). With increasing doses, central venous pressure as well as mean pulmonary artery pressure and enddiastolic pulmonary artery pressure decreased. No vasoconstriction was found in muscle tissue vessels even with large doses of dopamine. …
Inhibition of Peripheral Dopamine Metabolism and the Ventilatory Response to Hypoxia in the Rat
2014
Dopamine (DA) is a putative neurotransmitter in the carotid body engaged in the generation of the hypoxic ventilatory response (HVR). However, the action of endogenous DA is unsettled. This study seeks to determine the ventilatory effects of increased availability of endogenous DA caused by inhibition of DA enzymatic breakdown. The peripheral inhibitor of MAO – debrisoquine, or COMT – entacapone, or both combined were injected to conscious rats. Ventilation and its responses to acute 8 % O2 in N2 were investigated in a whole body plethysmograph. We found that inhibition of MAO augmented the hyperventilatory response to hypoxia. Inhibition of COMT failed to influence the hypoxic response. Ho…