Search results for "Dopamine"
showing 10 items of 660 documents
Electrophysiological and Neurochemical Characterization of 7-Nitroindazole and Molsidomine Acute and Sub-Chronic Administration Effects in the Dopami…
2009
Nitric oxide (NO) plays an important role in the integration of information processed by the basal ganglia nuclei. Accordingly, considerable evidence has emerged indicating a role for NO in pathophysiological conditions such as Parkinson’s disease (PD) and other neurodegenerative disorders. Despite these recent advances, the nitrergic modulation of the dopamine (DA) nigrostriatal system is still unclear. In order to fill this gap, in this study we used in vivo electrophysiology and ex vivo neurochemical analysis to further investigate the effect of NO signaling in rat substantia nigra pars compacta (SNc) and the striatum. Acute and subchronic (4 days) pharmacological manipulation of the NO …
Addictive-like behaviour for Acetaldehyde: involvement of D2 receptors
2013
Acetaldehyde (ACD), ethanol's first metabolite, is centrally active and shows rewarding and motivational properties. It is able to activate mesolimbic dopamine system, since it enhances neuronal firing of dopamine cells in ventral tegmental area and exerts dopamine release in the nucleus accumbens (Foddai et al., 2004; Melis et al., 2007; Deehan et al., 2013). ACD motivational properties are demonstrated by self-administration studies in rodents (Rodd et al., 2005), particularly behavioural evidence suggests that ACD could produce positive reinforcing effects in operant-conflict paradigms (Cacace et al., 2012). In order to shed light on neurobiological substrate underpinning ACD-related beh…
PET Studies of Net Blood—Brain Clearance of FDOPA to Human Brain: Age-Dependent Decline of [18F]Fluorodopamine Storage Capacity
2005
Conventional methods for the graphical analysis of 6-[18F]fluorodopa (FDOPA)/positron emission tomography (PET) recordings ( Kappin) may be prone to negative bias because of oversubtraction of the precursor pool in the region of interest, and because of diffusion of decarboxylated FDOPA metabolites from the brain. These effects may reduce the sensitivity of FDOPA/PET for the detection of age-related changes in dopamine innervations. To test for these biasing effects, we have used a constrained compartmental analysis to calculate the brain concentrations of the plasma metabolite 3- O-methyl-FDOPA (OMFD) during 120 mins of FDOPA circulation in healthy young, healthy elderly, and Parkinson's …
Higher doses of cabergoline further improve metabolic parameters in patients with prolactinoma regardless of the degree of reduction in prolactin lev…
2013
OBJECTIVE: Currently available studies that fully analyse the metabolic parameters in patients with prolactinoma are scarce and discordant. The aim of this study was to evaluate the metabolic effects of cabergoline (CAB) treatment in patients with newly diagnosed prolactinoma in relation to disease control and CAB dosage. DESIGN: This is a retrospective clinical-based therapy analysis. PATIENTS: Forty-three patients with prolactinoma (eight men, 35 women), aged 33·65 ± 11·23 years, were evaluated metabolically at baseline and after 12 months of CAB treatment. MEASUREMENTS: Body mass index (BMI), systolic and diastolic blood pressure, waist circumference (WC), lipid profile, haemoglobinA1c (…
Correlative gene expression pattern linking RNF123 to cellular stress–senescence genes in patients with depressive disorder: Implication of DRD1 in t…
2013
Abstract Background The expression level of the RNF1213 gene in blood cells has been identified as a disease risk marker, more than ten years before the diagnosis of depression ( Glahn et al., 2012 ). To explore the status of this gene in the acute depressive state we have quantified the expression of RNF123 in the blood leukocytes ( N =17), dorsolateral prefrontal and cingulate cortex ( N =24) of patients with diagnosed depression and of matched controls. We have measured the expression of the DRD1 gene as a “neuronal probe”. We have also quantified the mRNA of six genes previously identified as markers of the biopsychological stress associated with major depression: FOS, DUSP1, OGG1, STMN…
Asymmetry in dopamine D2/3 receptors of caudate nucleus is lost with age
2007
Molecular and functional imaging techniques reveal evidence for lateralization of human cerebral function. Based on animal data, we hypothesized that asymmetry in dopamine neurotransmission declines during normal aging. In order to test this hypothesis, we measured dopamine D2/3 receptor availability with [18F]desmethoxyfallypride-PET (DMFP) in putamen and caudate nucleus (NC) of 21 healthy, right-handed males (24-60 years; 35+/-10). For volumetric analysis, high-resolution T1-weighted MR-images were obtained in 18 of the PET-subjects in order to assess possible age-related decreases in NC and putamen volume. The calculated DMFP binding potentials (BP) showed a right-ward asymmetry in NC of…
Roxindole, a dopamine autoreceptor agonist, in the treatment of major depression
1993
Roxindole is a potent autoreceptor-“selective” dopamine agonist originally developed for the treatment of schizophrenic syndromes. The drug also inhibits 5-HT uptake and has 5-HT1A agonistic actions. In this open clinical trial 12 in-patients suffering from a major depressive episode (DSM-III-R) were treated with roxindole for 28 days in a fixed dosage of 15 mg per day. A reduction of at least 50% in HAMD-17 total scores was observed in 8 out of 12 patients after 4 weeks (mean HAMD-17 reduction of 56% in all patients), while 4 patients did not respond to roxindole treatment. Half of the patients showed a complete psychopathological remission (HAMD-17 <8). Roxindole's onset of antidepressant…
Lisuride, a dopamine D2 receptor agonist, and anticraving drug expectancy as modifiers of relapse in alcohol dependence
2002
Due to a central role of dopamine in mediating ethanol intake and dependence, the authors tested lisuride, a dopamine D2 receptor agonist, for relapse prevention in alcoholics. Psychological and neuroendocrine determinants of outcome were also assessed within the study. This double-blind, placebo-controlled randomized study comprised 120 alcoholics who were subjected to an intend-to-treat analysis (ITT). After hospital detoxification, patients received an outpatient rehabilitation program and either the study medication or placebo for 6 months and follow-up for another 6 months without medication. Pharmacological and psychological effects on relapse and times to first drink were assessed us…
A ventral striatal prediction error signal in human fear extinction learning.
2021
Animal studies have shown that the prediction error (PE) signal that drives fear extinction learning is encoded by phasic activity of midbrain dopamine (DA) neurons. Thus, the extinction PE resembles the appetitive PE that drives reward learning. In humans, fear extinction learning is less well understood. Using computational neuroimaging, a previous study from our group reported hemodynamic activity in the left ventral putamen, a subregion of the ventral striatum (VS), to correlate with a PE function derived from a formal associative learning model. The activity was modulated by genetic variation in a DA-related gene. To conceptually replicate and extend this finding, we here asked whether…
Dopamine D2/3 receptor occupancy by quetiapine in striatal and extrastriatal areas
2010
Quetiapine is next to clozapine an antipsychotic agent that exerts hardly any extrapyramidal side-effects at clinical efficacious doses. Some previous receptor occupancy studies reported preferential extrastriatal D2/3 receptor (D2/3R)-binding properties of second-generation antipsychotics and suggested this as possible reason for improved tolerability. This positron emission tomography (PET) investigation was designed to compare the occupancy of dopamine D2/3Rs by quetiapine in striatal and extrastriatal brain regions. Therefore, a cohort of 16 quetiapine-treated psychotic patients underwent an [18F]fallypride (FP) PET scan. Due to the high affinity of FP and its comparatively long half-li…