Search results for "Accumbens"
showing 10 items of 99 documents
Impaired alcohol-induced dopamine release in the nucleus accumbens in an inflammatory pain model: behavioral implications in male rats
2020
ABSTRACT Recent studies have drawn the attention to the link between alcohol use disorder and the presence of pain. Indeed, the correct management of pain in patients with a previous history of alcohol use disorder has been reported to decrease the risk of relapse in alcohol drinking, suggesting that in this prone population, pain may increase the vulnerability to relapse. Previous data in male rats revealed that inflammatory pain desensitizes mu-opioid receptors in the ventral tegmental area and increases intake of high doses of heroin. Owing to the relevant role of mu-opioid receptors in alcohol effects, we hypothesize that pain may also alter alcohol reinforcing properties and therefore …
Gene Transcription Alterations Associated with Decrease of Ethanol Intake Induced by Naltrexone in the Brain of Wistar Rats
2006
Preclinical and clinical studies suggest that the administration of the opioid antagonist naltrexone decreases the intake of ethanol. However, the neuroplastic adaptations in the brain associated to reduction of ethanol consumption remains to be elucidated. The aim of the study was to identify gene transcription alterations underlying the attenuation of voluntary ethanol intake by administration of naltrexone in rats. Increasing doses of naltrexone (0.7 mg/kg, 4 days and 1.4 mg/kg/day, 4 days) to rats with acquired high preferring ethanol consumption (>3.5 g of ethanol/kg/day) decreased voluntary ethanol intake (50%). Voluntary ethanol consumption altered mu-opioid receptor function in the …
Effects of Intraaccumbens Microinjections of Quinpirole on Head Turning and Circling Movement in the Rat
1998
This study was designed to evaluate whether nucleus accumbens dopamine D2 receptors are involved in the initiation of the movement, as distinguished from its execution. For this purpose, the effects of the quinpirole-induced increase of nucleus accumbens dopamine D2 receptor activity were observed on specific parameters of the circling behavior and of its first stage, the head-turning (HT) movement. The experiments were performed on rats with unilateral 6-hydroxydopamine (6-OHDA) lesion of the pars compacta of the substantia nigra and d-amphetamine i.p. (3 mg/kg). Bilateral intraaccumbens microinjections of quinpirole (1, 5, and 10 microg/0.5 microl), an agonist of the D2 receptor family, w…
Activation of a ΔFOSB dependent gene expression pattern in the dorsolateral prefrontal cortex of patients with major depressive disorder
2010
Abstract Background A ΔFOSB mediated transcriptional response in the nucleus accumbens (NAc) is induced by chronic social stress in rodent and a 50% down-regulation of ΔFOSB has been also reported in the NAc of eight depressed subjects. To evaluate the role of ΔFOSB in the prefrontal cortex which is critically involved in negative cognitive bias associated with major depressive disorder (MDD) we have quantified the mRNA levels of ΔFOSB and of five of its major target genes in the Brodmann area 46 from 24 patients with MDD (11 with psychotic symptoms) and 12 controls. Method Expression of the six genes has been quantified by a real-time quantitative PCR method: ΔFOSB , GRIA2 (encoding the Gl…
Increased neuropeptide Y mRNA expression in striatum in Parkinson's disease.
2003
High levels of neuropeptide Y (NPY) are found in basal ganglia where it is co-localised with somatostatin (SOM) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH/d) in a population of striatal GABA containing interneurones. Although alterations occur in the levels of various neuropeptides in basal ganglia in Parkinson’s disease (PD), it is not known whether NPY is affected. Using in situ hybridisation immunohistochemistry, we have examined the distribution of NPY mRNA in the caudate nucleus, putamen and nucleus accumbens of normal individuals and patients with PD. NPY mRNA was weakly expressed in the caudate nucleus, putamen and nucleus accumbens in normal individuals with a…
Opposite effects of γ1- and γ2-melanocyte stimulating hormone on regulation of the dopaminergic mesolimbic system in rats
2004
By use of the brain microdialysis technique we show that administration of gamma(1)-melanocyte stimulating hormone (gamma(1)-MSH) into the ventral tegmental area of anaesthetized rats causes an increase in the release of extracellular dopamine and its metabolite 3,4-dihydroxyphenylacetic acid in the nucleus accumbens, while gamma(2)-MSH causes the opposite effect. Moreover, gamma(2)-MSH pre-treatment considerably reduced the gamma(1)-MSH-induced effects. Our findings suggest an opposing action of two gamma-MSH-activated pathways on the mesolimbic dopaminergic system, which could be important in the maintenance of a balanced psychoactivation state.
Sex differences in nucleus accumbens transcriptome profiles associated with susceptibility versus resilience to subchronic variable stress
2015
Depression and anxiety disorders are more prevalent in females, but the majority of research in animal models, the first step in finding new treatments, has focused predominantly on males. Here we report that exposure to subchronic variable stress (SCVS) induces depression-associated behaviors in female mice, whereas males are resilient as they do not develop these behavioral abnormalities. In concert with these different behavioral responses, transcriptional analysis of nucleus accumbens (NAc), a major brain reward region, by use of RNA sequencing (RNA-seq) revealed markedly different patterns of stress regulation of gene expression between the sexes. Among the genes displaying sex differe…
Mesolimbic dopaminergic system activity as a function of food reward: A microdialysis study
1996
The mesolimbic dopaminergic system (MDS) has been shown to be implicated in feeding behaviors. The present experiment was conducted to examine the effects of the sensory properties of food ingested on MDS activity. Microdialysis coupled to high-performance liquid chromatography with electrochemical detection was employed to measure the extracellular levels of dopamine (DA) and its main metabolites (DOPAC and HVA) in the nucleus accumbens of freely moving rats. During microdialysis sessions rats had access or not to powdered foods varying in palatability: short cakes as highly palatable (HP) food and regular chow as low palatable (LP) food. In the absence of food, there were no alterations i…
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 …