Search results for "339"

Sensitization to the rewarding effects of morphine depends on dopamine

2005

The influence of dopamine (DA) on sensitization to the rewarding effects of morphine was evaluated. The effects of pre-treatment with saline or morphine plus naloxone, CGS 10746B, haloperidol, SCH 23390 and raclopride, on the place conditioning induced by 2 mg/kg morphine were evaluated. This dose was ineffective in saline pre-treated animals but induced a clear conditioned place preference in mice pre-treated with morphine, CGS 10746B or haloperidol. Conversely, animals pre-treated with morphine plus naloxone, CGS 10746B, SCH 23390, raclopride and the high dose of haloperidol did not acquire place preference. Our results demonstrated that DA release and subsequent DA D1 and D2 receptor act…

Role of dopamine neurotransmission in the long-term effects of repeated social defeat on the conditioned rewarding effects of cocaine

2016

Numerous studies report that social defeat stress alters dopamine (DA) neurotransmission in several areas of the brain. Alterations of the mesolimbic dopaminergic pathway are believed to be responsible for the increased vulnerability to drug use observed as a result of social stress. In the present study, we evaluated the influence of DA receptors on the long-term effect of repeated social defeat (RSD) on the conditioned rewarding and reinstating effects of cocaine. For this purpose, the D1R antagonist SCH 23390 and the D1R antagonist raclopride were administered 30 min before each social defeat and a cocaine-induced CPP procedure was initiated three weeks later. The expression of the D1R a…

Hippocampal dopamine receptors modulate the motor activation and the increase in dopamine levels in the rat nucleus accumbens evoked by chemical stim…

2005

A number of studies have shown that chemical stimulation (using N-methyl-D-aspartate (NMDA) infusions) or electrical stimulation of the ventral hippocampus (VH) elicits locomotor activation and sustained increases in nucleus accumbens (NAc) dopamine (DA) levels in rodents. How DA neurotransmission in NAc is involved in these effects has also been well established. However, the modulatory role of the DA receptors located in VH is not yet fully understood. The purpose of this study was to characterize the role played by VH D1 and D2 subtype receptors in both the locomotor activation and NAc DA increases induced by NMDA stimulation of the VH. This was assessed by studying how retrodialysis app…

Hippocampal dopamine receptors modulate cFos expression in the rat nucleus accumbens evoked by chemical stimulation of the ventral hippocampus

2005

Recently, we have shown that D1 and D2 receptors in the ventral hippocampus (VH) modulate both the locomotor activation and the increase in dopamine (DA) levels in the rat nucleus accumbens (NAc) induced by NMDA stimulation of the VH. In the present study we analyze the possible role of VH D1 and D2 receptors in the modulation of the cFos expression in NAc (core and shell subregions) and in dorsal striatum. This was assessed by immunohistochemical analysis of cFos expression in the rat brains after retro-dialysis application of NMDA (50mM, 10 min) into VH, in absence and in presence of either the D1/D5 receptor antagonist SCH 23390 (100 and 250 microM, 60 min) or the D2 receptor antagonist …

Effects of two selective dopaminergic antagonists on ethologically-assessed encounters in male mice

1993

Abstract 1. Although it is accepted that dopaminergic antagonists suppress aggressive behaviour, the drugs used have been relatively non-selective or specific to the D2 receptor. 2. The selective D1 antagonist, SCH 23390, makes it possible to evaluate the impact of this receptor on aggressive behaviour. 3. The effects of SCH 23390 and Spiperone (a D2 antagonist) on the aggressive behaviour of mice were assessed employing a “standard opponent” test. 4. Both drugs markedly decreased aggressive behaviour whilst increasing immobility. However, whilst SCH 23390 increased immobility to a small extent, Spiperone, produced a general decline in active behaviours. 5. It appears that the D1 receptor i…

Dopamine antagonists impair ‘red-green’ discrimination in goldfish after intravitreal injection

1995

Color vision in goldfish is tetrachromatic. However, under mesopic illumination conditions the L-cones do not contribute to wavelength discrimination, and color vision becomes trichromatic. To investigate the role of dopamine in light adaptation, we tested the effect of the unspecific dopamine antagonist haloperidol and of the specific dopamine Dl receptor antagonists SCH 23390 and SKF 83566-biotinyl in behavioral wavelength discrimination experiments. After injection of dopamine antagonists into the vitreous, a reduction in wavelength discrimination was observed in the range between 560 nm and 630 nm but not in the range between 404 nm and 501 nm.

Los talleres artesanos-artísticos de la Valencia del siglo XX

2011

Hvorfor løper du? En undersøkelse og kartlegging av motiver og lidenskap i løpskulturen Laubejentan og Laubegudan i Farsund.

2015

Masteroppgave idrettsvitenskap- Universitetet i Agder, 2015 Hensikten med denne studien er å undersøke og kartlegge betydningen av motiver og lidenskap i løpskulturen Laubejentan og Laubegudan i Farsund. I tillegg er det et mål å gi en deskriptiv beskrivelse av gruppen og dens medlemmer. 40 medlemmer deltok i undersøkelsen. Datainnsamlingen ble gjort gjennom en metodetriangulering, kvantitativ ved spørreskjema og kvalitativt gjennom intervju av nøkkelpersoner. For å måle lidenskap ble «The Passion Scale» (TPS) brukt, mens for å måle motiver ble et åpent spørsmål i spørreundersøkelsen benyttet. Resultatet viser at sosiale motiver er viktigste grunn for å være medlem i Laubejentan og Laubegud…

La gestion des betteraves adventices résistantes à un herbicide: une approche par simulation

2007

National audience; Les variétés de betteraves sucrières génétiquement modifiées (GM) résistantes à un herbicide sont, a priori, intéressantes dans des champs fortement infestés par la betterave adventice. Cependant, la montée à fleurs de ces betteraves GM peut entraîner l’apparition d’individus résistants, via la dispersion de pollen. Nous avons développé et utilisé le modèle GENESYS-Betterave pour simuler, à l’échelle d’une petite région agricole, l’impact des pratiques culturales sur la dispersion du transgène. Il permet d'identifier des stratégies pour contrôler les adventices et limiter l'apparition de populations résistantes en zone de production de betterave sucrière. L’utilisation de…

Influence of Menstrual Cycle or Hormonal Contraceptive Phase on Physiological Variables Monitored During Treadmill Testing

2021

Purpose: To examine the influence of menstrual cycle (MC) and hormonal contraceptive (HC) cycle phases on physiological variables monitored during incremental treadmill testing in physically active women (eumenorrheic, EUM = 16 and monophasic HC-users, CHC = 12). Methods: Four running tests to exhaustion were performed at bleeding, mid follicular (mid FOL)/active 1, ovulation/active 2, and mid luteal (mid LUT)/inactive. HC and MC phases were confirmed from serum hormones. Heart rate (HR), blood lactate (Bla), and VO˙ 2 were monitored, while aerobic (AerT) and anaerobic (AnaT) thresholds were determined. VO˙ 2peak, maximal running speed (RUNpeak), and total running time (RUNtotal) were recor…