The magnitude and the extinction duration of the cocaine-induced conditioned locomotion-activated response are related to the number of cocaine injections paired with the testing context in C57BL/6J mice

in Behavioural Brain Research (2003), 145(1-2), 113-123

Behavioural activation repeatedly induced by a stimulant in rodents can persist in the absence of the drug if the animals are tested in the context where the drug was previously given, a phenomenon often ... [more ▼]

Behavioural activation repeatedly induced by a stimulant in rodents can persist in the absence of the drug if the animals are tested in the context where the drug was previously given, a phenomenon often explained in terms of Pavlovian conditioning. The aim of this study was to verify whether the amplitude of the putative CR (the drug-like activity) increases with the number of the US-CS associations (the number of drug-context pairings), one of the most representative rules of Pavlovian conditioning. The effect of the number of trials on the speed of extinction was also considered. C57BL/6J mice received 3, 6 or 12 once-daily injections of either saline or 12 mg/kg (-)-cocaine hydrochloride (s.c.) in the same test context, a photocell activity-box in which they were tested for 60 min after every injection. Other groups received the same treatments outside of the test context (being placed in a novel cage tub after each injection). Twenty-four hours after the last treatment session, all mice were challenged with saline in the test context (test for conditioned activity), extinction sessions taking place on the three subsequent days. Sensitisation to the locomotor-activating effect of cocaine developed only amongst the animals injected 6 or 12 times, the magnitude of the last sensitised response being comparable for these two injections regimen. On saline challenge, only the animals that had received 6 or 12 cocaine injections showed significant conditioned activity (CR), with the greatest response occurring following 12 injections. The 6-trial group reached the level of non-significance after fewer extinction sessions than the 12-trial group; however, the rates of extinction did not differ (comparable regression coefficients and quasi-parallel curves). These results suggest that the amplitude of the CR (cocaine-like stimulation after saline), and perhaps less convincingly the duration of extinction, are functions of the number of the US-CS (cocaine-context) pairings, supporting the Pavlovian nature of post-sensitisation placebo drug-like effects. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲]

Levels and enantiomeric signatures of methyl sulfonyl PCB and DDE metabolites in livers of harbor porpoises (Phocoena phocoena) from the southern North Sea

in Environmental Science & Technology (2003), 37(20), 4573-4578

The concentration of 26 methyl sulfonyl metabolites of polychlorinated biphenyls (MeSO2-PCBs) and of p,p'-DDE (MeSO2-DDE) were determined in 19 liver samples from harbor porpoises (Phocoena phocoena ... [more ▼]

The concentration of 26 methyl sulfonyl metabolites of polychlorinated biphenyls (MeSO2-PCBs) and of p,p'-DDE (MeSO2-DDE) were determined in 19 liver samples from harbor porpoises (Phocoena phocoena) stranded between 1997 and 2000 on the Belgian and French North Sea Coasts. The total concentration of MeSO2-PCBs ranged from 39 to 4221 ng/g lipid weight (lw) and were generally higher in adults (age >2 yr, range 969-4221 ng/g lw) than in juveniles (age <2 yr, range 39-1815 ng/g lw). The concentrations of MeSO2-DDE were generally also higher in adults (2196 ng/g lw) than in juveniles (0.5-60 ng/g lw). Congeners 3- and 4-MeSO2-CB101 were the dominating metabolites in all samples. Due to their preferential retention in the liver, the MeSO2-PCB congeners could be divided into two groups. The first group was dominated by the 3-MeSO2-PCB congeners and consisted of MeSO2-CB31, -CB49, -CB52, -CB87, and -CB101, which all have a 2,5-chlorine substitution in the phenyl ring containing the methyl sulfonyl group. The second group was dominated by the 4-MeSO2-PCB congeners and consisted of MeSO2-CB64, -CB91, -CB110, and -CB132, which all have a 2,3,6-chlorine substitution. The ratios of sum of PCBs/sum of MeSO2-PCBs and p,p-DDE/MeSO2-DDE differed greatly between individual subjects and ranged from 15 to 419 and from 17 to 1088, respectively. The ratio between the precursor PCB congeners and their corresponding metabolites ranged from 0.6 (CB49) to 175 (CB174). Enantiomeric fractions (EFs) for MeSO2-PCB atropisomers, which include 3-MeSO2-CB132, 3-MeSO2-CB149, 4-MeSO2-CB149, 3-MeSO2-CB174, and 4-MeSO2-CB174, were also measured in 8 out of the 19 subjects. High enantiomeric excess (EF > 0.73 or EF < 0.23) for the measured chiral MeSO2-PCB congeners was found in all samples. This result may suggest that one atropisomer may be preferentially formed in harbor porpoises or that the atropisomers are retained in a highly selective manner. [less ▲]

Participation à l'émission de Canal Zoom sur la qualité différenciée

Diverse speeche and writing (2003)

Tomographie a emission de positons: une revolution en cancerologie?

in Revue du Praticien (La) (2003), 53(15), 1629-30

Bulletin agrométéorologique - Septembre 2003

in Bulletin Agrométéorologique (2003)

Le mois de septembre a été caractérisé par des précipitations et des vitesses moyennes du vent faibles. Par contre, les températures et le rayonnement furent relativement élevés sur l’ensemble du pays ... [more ▼]

Le mois de septembre a été caractérisé par des précipitations et des vitesses moyennes du vent faibles. Par contre, les températures et le rayonnement furent relativement élevés sur l’ensemble du pays. Cette année, les rendements prévus pour les cultures de maï s fourrager et de betterave sucrière, sont respectivement équivalents et inférieurs à ceux observés en 2002. [less ▲]

Specific innervation of aromatase neurons by substance P fibers in the dorsal horn of the spinal cord in quail

in Journal of Comparative Neurology (2003), 465(2), 309-318

The enzyme aromatase catalyzes the production of estrogens in the dorsal horn of the spinal cord where most of the nociceptive primary afferent fibers terminate. Numerous estrogen receptors are present in ... [more ▼]

The enzyme aromatase catalyzes the production of estrogens in the dorsal horn of the spinal cord where most of the nociceptive primary afferent fibers terminate. Numerous estrogen receptors are present in this area and the control of spinal aromatase activity is thought to play an important role in the estrogenic control of nociception. The coexistence of aromatase and nociceptive terminals suggests a role for aromatase cells in pain-related processes, but whether terminals releasing nociceptive neuropeptides (e.g., substance P) actually contact aromatase neurons is unknown and the factors that control spinal aromatase activity have not yet been identified. In the present study we analyzed by double-label immunocytochemistry the distribution in the Japanese quail spinal cord, of aromatase and of substance P or its receptor (neurokinin 1 receptor). All antigens were mainly localized in laminae I and II as observed in mammals. Most aromatase neurons were colocalized with neurokinin 1 receptors and were in close apposition with substance P-immunoreactive fibers. These results suggest that aromatase neurons are responsive to noxious stimulation and may participate in the control of nociception. Furthermore, spinal aromatase activity could be controlled by substance P through a regulation of the aromatase gene transcription as reported for the mouse diencephalon and/or through neurokinin 1 receptor-dependent phosphorylation of the aromatase protein. [less ▲]

Les mammites en élevage laitie. Outils et stratégies de diagnostic

Conference (2003, October 11)

GENIE: un précurseur pour Darwin

Scientific conference (2003, October 09)

L'instrument GENIE, un projet commun de l'ESA (Agence Spatiale Européenne) et de l'ESO (Observatoire Européen Austral), sera installé en 2007 sur le site du VLTI (Paranal, Chili). Cet instrument ... [more ▼]

L'instrument GENIE, un projet commun de l'ESA (Agence Spatiale Européenne) et de l'ESO (Observatoire Européen Austral), sera installé en 2007 sur le site du VLTI (Paranal, Chili). Cet instrument interférométrique recombinera de façon destructive la lumière infrarouge collectée par deux ou plusieurs Very Large Telescopes, permettant ainsi d'étudier l'environnement d'objets brillants avec une haute résolution angulaire. Son objectif principal est de valider le concept du "nulling interferometer", de gagner de l'expérience dans le design et l'opération d'un tel instrument, et de tester certaines des nouvelles technologies nécessaires pour Darwin. GENIE préparera aussi le programme scientifique de Darwin en détectant et caractérisant d'éventuels disques de poussière autour des étoiles cibles de Darwin. Cette étude permettra d'écarter les cibles inappropriées pour la recherche de planètes habitables. GENIE obtiendra également des spectres basse résolution pour le rayonnement thermique de quelques exoplanètes géantes. [less ▲]

Exploration des processus intentionnels et automatiques d’inhibition dans la maladie d’Alzheimer

in Revue Neurologique (2003, October 09), 159

Nucleotidaktivierte Di- und Oligosaccharide sowie Verfahren zu deren Herstellung

Patent (2003)