Salsolinol Facilitates Glutamatergic Transmission to Dopamine Neurons in the Posterior Ventral Tegmental Area of Rats

Although in vivo evidence indicates that salsolinol, the condensation product of acetaldehyde and dopamine, has properties that may contribute to alcohol abuse, the underlying mechanisms have not been fully elucidated. We have reported previously that salsolinol stimulates dopamine neurons in the posterior ventral tegmental area (p-VTA) partly by reducing inhibitory GABAergic transmission, and that ethanol increases glutamatergic transmission to VTA-dopamine neurons via the activation of dopamine D1 receptors (D1Rs). In this study, we tested the hypothesis that salsolinol stimulates dopamine neurons involving activation of D1Rs. By using whole-cell recordings on p-VTA-dopamine neurons in acute brain slices of rats, we found that salsolinol-induced increase in spike frequency of dopamine neurons was substantially attenuated by DL-2-amino-5-phosphono-valeric acid and 6, 7-dinitroquinoxaline-2, 3-dione, the antagonists of glutamatergic N-Methyl-D-aspartic acid and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. Moreover, salsolinol increased the amplitude of evoked excitatory postsynaptic currents (EPSCs) and the frequency but not the amplitude of spontaneous EPSCs. Additionally, SKF83566, a D1R antagonist attenuated the salsolinol-induced facilitation of EPSCs and of spontaneous firing of dopamine neurons. Our data reveal that salsolinol enhances glutamatergic transmission onto dopamine neurons via activation of D1Rs at the glutamatergic afferents in dopamine neurons, which contributes to salsolinol's stimulating effect on p-VTA dopamine neurons. This appears to be a novel mechanism which contributes toward rewarding properties of salsolinol

Projecting the Medium-Term: Outcomes and Errors for GDP Growth

The focus of this paper is the evaluation of a very popular method for potential output estimation and medium-term forecasting - the production function approach - in terms of predictive performance. For this purpose, a forecast evaluation for the three to five years ahead predictions of GDP growth for the individual G7 countries is conducted. To carry out the forecast performance check a particular testing framework is derived that allows the computation of robust test statistics given the specific nature of the generated out-of sample forecasts. In addition, medium-term GDP projections from national and international institutions are examined and it is assessed whether these projections convey a reliable view about future economic developments and whether there is scope for improving their predictive content

Chaotic heat transfer for heat exchanger design and comparison with a regular regime for a large range of Reynolds numbers

An experimental comparison is made over a large range of Reynolds numbers (from 30 to 30,000) between two shell-and-tube heat exchangers having the same heat-transfer area and same number of bends, but different configurations: one has a helical configuration (regular flow), the other has a chaotic one (chaotic advection flow). Both are composed of 33 bends with circular tube cross section (inside diameter 23 mm) and are immersed in a closed shell. The working fluids are Newtonian with different Prandtl numbers (820, 230, 75 and 6.5) in order to cover the large-Reynolds-number range. The comparison is made by using a criterion L that takes into account thermal performance and energy expenditure. The results show that at low Reynolds numbers, heat transfer is higher and heating more homogeneous for chaotic advection flow, with no increase in energy expenditure. At high Reynolds numbers, the configuration has no influence on heat transfer. When the Prandtl number increases, the heat transfer increases. The flows have also been visualized by laser-induced fluorescence to assess the improvement of mixing in the chaotic configuration. (C) 2000 Elsevier Science Ltd. All rights reserved

Diagnostic d'un plasma de mélange CO2, CO, N2 et H2, par spectroscopie optique d'émission atomique et moléculaire

Rapport d'étude dans le cadre du contrat EUROPLASM

Are basic auditory processes involved in source-monitoring deficits in patients with schizophrenia?

International audiencePatients with schizophrenia (SZ) display deficits in both basic non-verbal auditory processing and source-monitoring of speech. To date, the contributions of basic auditory deficits to higher-order cognitive impairments, such as source-monitoring, and to clinical symptoms have yet to be elucidated. The aim of this study was to investigate the deficits and relationships between basic auditory functions, source-monitoring performances, and clinical symptom severity in SZ. Auditory processing of 4 psychoacoustic features (pitch, intensity, amplitude, length) and 2 types of source-monitoring (internal and reality monitoring) performances were assessed in 29 SZ and 29 healthy controls. Clinical symptoms were evaluated in patients with the Positive And Negative Syndrome Scale. Compared to the controls, SZ individuals in showed significant reductions in both global basic auditory processing (p < .0005, d = 1.16) and source-monitoring (p < .0005, d = 1.24) abilities. Both deficits correlated significantly in patients and across groups (all p < .05). Pitch processing skills were negatively correlated with positive symptom severity (r = -0.4, p < .05). A step-wise regression analysis showed that pitch discrimination was a significant predictor of source-monitoring performance. These results suggest that cognitive mechanisms associated with the discrimination of basic auditory features are most compromised in patients with source-monitoring disability. Basic auditory processing may index pathophysiological processes that are critical for optimal source-monitoring in schizophrenia and that are involved in positive symptoms

La codification en Belgique :le droit de la consommation dans le nouveau Code de droit économique: in n L. Arcelin Lécuyer (éd.), Quels moyens pour un droit de la consommation effectif et efficace à l’ère numérique ?

Cet article, rédigé suite à un colloque international tenu à l’Université de La Rochelle le 10 octobre 2014 ( intervention consultable ici :http://portail-video.univ-lr.fr/La-pertinence-d-un-code-de-la), a pour objet de montrer et analyser l’approche suivie en droit belge dans le domaine de la codification du droit de la consommation. Cette approche a plusieurs particularités :au contraire de pays comme l’Allemagne, les Pays-Bas ou l’Autriche, la Belgique a d’emblée régi le droit de la consommation en-dehors Code civil ;mais, par ailleurs, au contraire d’autres Etats membres de l’Union européenne, comme la France, elle n’a pas non plus fait le choix de l’adoption d’un Code propre au droit de la consommation. Depuis l’origine (récente) de ce droit en Belgique, le législateur régit en un seul corps de texte le droit de la concurrence déloyale (les normes de loyauté dans les rapports entre professionnels), d’une part, et le droit de la consommation (normes d’information et de protection des consommateurs), de l’autre, ce qui présente des avantages mais pose aussi des problèmes aigus lors de la transposition des directives européennes lorsque celles-ci ne concernent que le droit de la consommation.info:eu-repo/semantics/publishe

Wireless instantaneous neurotransmitter concentration system-based amperometric detection of dopamine, adenosine, and glutamate for intraoperative neurochemical monitoring - laboratory investigation

Object&nbsp; In a companion study, the authors describe the development of a new instrument named the Wireless Instantaneous Neurotransmitter Concentration System (WINCS), which couples digital telemetry with fast-scan cyclic voltammetry (FSCV) to measure extracellular concentrations of dopamine. In the present study, the authors describe the extended capability of the WINCS to use fixed potential amperometry (FPA) to measure extracellular concentrations of dopamine, as well as glutamate and adenosine. Compared with other electrochemical techniques such as FSCV or high-speed chronoamperometry, FPA offers superior temporal resolution and, in combination with enzyme-linked biosensors, the potential to monitor nonelectroactive analytes in real time.Methods&nbsp; The WINCS design incorporated a transimpedance amplifier with associated analog circuitry for FPA; a microprocessor; a Bluetooth transceiver; and a single, battery-powered, multilayer, printed circuit board. The WINCS was tested with 3 distinct recording electrodes: 1) a carbon-fiber microelectrode (CFM) to measure dopamine; 2) a glutamate oxidase enzyme&ndash;linked electrode to measure glutamate; and 3) a multiple enzyme&ndash;linked electrode (adenosine deaminase, nucleoside phosphorylase, and xanthine oxidase) to measure adenosine. Proof-of-principle analyses included noise assessments and in vitro and in vivo measurements that were compared with similar analyses by using a commercial hardwired electrochemical system (EA161 Picostat, eDAQ; Pty Ltd). In urethane-anesthetized rats, dopamine release was monitored in the striatum following deep brain stimulation (DBS) of ascending dopaminergic fibers in the medial forebrain bundle (MFB). In separate rat experiments, DBS-evoked adenosine release was monitored in the ventrolateral thalamus. To test the WINCS in an operating room setting resembling human neurosurgery, cortical glutamate release in response to motor cortex stimulation (MCS) was monitored using a large-mammal animal model, the pig.Results &nbsp; The WINCS, which is designed in compliance with FDA-recognized consensus standards for medical electrical device safety, successfully measured dopamine, glutamate, and adenosine, both in vitro and in vivo. The WINCS detected striatal dopamine release at the implanted CFM during DBS of the MFB. The DBS-evoked adenosine release in the rat thalamus and MCS-evoked glutamate release in the pig cortex were also successfully measured. Overall, in vitro and in vivo testing demonstrated signals comparable to a commercial hardwired electrochemical system for FPA.Conclusions&nbsp; By incorporating FPA, the chemical repertoire of WINCS-measurable neurotransmitters is expanded to include glutamate and other nonelectroactive species for which the evolving field of enzyme-linked biosensors exists. Because many neurotransmitters are not electrochemically active, FPA in combination with enzyme-linked microelectrodes represents a powerful intraoperative tool for rapid and selective neurochemical sampling in important anatomical targets during functional neurosurgery