Search results for "Dopamine"
showing 10 items of 660 documents
7-nitroindazole protects striatal dopaminergic neurons against MPP+-induced degeneration: an in vivo microdialysis study.
2007
The neuropathological hallmark of Parkinson's disease (PD) is the selective degeneration of dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNc). In this study, using a microdialysis technique, we investigated whether an inhibitor of neuronal nitric oxide synthase (nNOS), 7-nitrindazole (7-NI), could protect against DAergic neuronal damage induced by in vivo infusion of 1-methyl-4-phenylpiridinium iodide (MPP(+)) in freely moving rats. Experiments were performed over 2 days in three groups of rats: (a) nonlesioned, (b) MPP(+)-lesioned, and (c) 7-NI pretreated MPP(+)-lesioned rats. On day 1, control rats were perfused with an artificial CSF, while 1 mM MPP(+) was infuse…
Induction of brain CYP2E1 changes the effects of ethanol on dopamine release in nucleus accumbens shell.
2009
CYP2E1 is an important enzyme involved in the brain metabolism of ethanol that can be induced by chronic consumption of alcohol. Recent works have highlighted the importance of this system in the context of the behavioural effects of ethanol. Unfortunately, the underlying neurochemical events for these behavioural changes, has not been yet explored. In this work, we have started this exploration by analyzing the possible changes in the neurochemical response of the mesolimbic system to ethanol after pharmacological induction of brain CYP2E1. We have used the dopamine extracellular levels in nucleus accumbens (NAc) core and shell, measured by means of microdialysis in vivo, as an index of th…
Local salsolinol modulates dopamine extracellular levels from rat nucleus accumbens: shell/core differences.
2008
Salsolinol (SAL), a condensation product of dopamine and acetaldehyde that appears in the rat and human brain after ethanol ingestion, has been largely implicated in the aetiology of alcoholism. Although the behavioural consequences of systemic or intracerebral SAL administrations have been described, the neurochemical effects of pharmacologically relevant doses of SAL and other tetrahydroisoquinolines (THIQs) in the brain areas involved in alcohol addiction are practically unknown. To gain an insight into this topic, male Wistar rats were stereotaxically implanted with one concentric microdialysis probe in either the shell or the core of the nucleus accumbens (NAc). Treatments involved loc…
Aspirin protects striatal dopaminergic neurons from neurotoxin-induced degeneration: an in vivo microdialysis study.
2006
The effect of aspirin on dopaminergic neuronal damage induced by in vivo infusion of 1-methyl-4-phenylpiridinium iodide (MPP(+)) and 6-hydroxydopamine (6-OHDA) was studied in rats, using microdialysis. Rat striata were perfused with 1 mM MPP(+) or 6-OHDA for 10 min, causing peak levels of dopamine (DA) in the dialytic fluid, after 40 min. After 24 h, 1 mM MPP(+) was perfused again for 10 min and DA levels measured in the dialytic fluid, as an index of neuronal cell integrity. Pretreatment with Aspidol (lysine acetylsalicylate), 180 mg/kg i.p., 1 h before MPP(+) or 6-OHDA perfusion, did not modify DA extracellular output, on day 1, but restored MPP(+)-induced DA release on day 2, indicating …
Influence of the amount of food ingested on mesolimbic dopaminergic system activity: a microdialysis study.
1996
Abstract The mesolimbic dopaminergic system (MDS) has been shown to be activated by ingestive behaviors, and it has been suggested that this activation may be related to the rewarding properties of foods. Because rats eat more when given a more palatable diet, this study was undertaken to determine the relationship between the amount of food ingested and DA release in the nucleus accumbens of freely moving rats. The extracellular levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured by high-performance liquid chromatography with electrochemical detection on microdialysis samples from the nucleus accumbens. Each rat underwent three microdia…
Induction of conditioned place preference and dopamine release by salsolinol in posterior VTA of rats: involvement of μ-opioid receptors.
2011
Salsolinol (Sal), locally administered into the posterior VTA (pVTA) of rats, produces psychomotor responses and reinforcing effects, probably, through the activation of μ-opioid receptors (MORs). The neurochemical correlates of these phenomena are, however, practically unknown. In this paper, we explore the neurochemical events and the mechanisms involved in these behaviors. To do that, we test the ability of Sal, directly microinjected into the pVTA, to induce conditioned place preference (CPP) and to increase dopamine levels in the nucleus accumbens shell. Bilateral injections of 30 pmol of Sal induced a strong CPP (rats spent around 70% of the total test time), a result that could be ex…
Opposite motor responses elicited by ethanol in the posterior VTA: The role of acetaldehyde and the non-metabolized fraction of ethanol
2013
Recent electrophysiological evidence suggests that ethanol simultaneously exerts opposite effects on the activity of dopamine (DA) neurons in the ventral tegmental area (VTA) through two parallel mechanisms, one promoting and the other reducing the GABA release onto VTA DA neurons. Here we explore the possible behavioural implications of these findings by investigating the role displayed by acetaldehyde (the main metabolite of ethanol) and the non-metabolized fraction of ethanol in motor activity of rats. We analyse the appearance of motor activation or depression after intra-VTA administration of ethanol in rats subjected to different pharmacological pre-treatments designed to preferential…
Tetrahydroisoquinolines as dopaminergic ligands: 1-Butyl-7-chloro-6-hydroxy-tetrahydroisoquinoline, a new compound with antidepressant-like activity …
2009
International audience; Three series of 1-substituted-7-chloro-6-hydroxy-tetrahydroisoquinolines (1-butyl-, 1-phenyl- and 1-benzyl derivatives) were prepared to explore the influence of each of these groups at the 1-position on the affinity for dopamine receptors. All the compounds displayed affinity for D(1)-like and/or D(2)-like dopamine receptors in striatal membranes, and were unable to inhibit [(3)H]-dopamine uptake in striatal synaptosomes. Different structure requirements have been observed for adequate D(1) or D(2) affinities. This paper details the synthesis, structural elucidation, dopaminergic binding assays, structure-activity relationships (SAR) of these three series of isoquin…
Role of the dopaminergic system in the acquisition, expression and reinstatement of MDMA-induced conditioned place preference in adolescent mice.
2012
Background The rewarding effects of 3,4-methylenedioxy-metamphetamine (MDMA) have been demonstrated in conditioned place preference (CPP) procedures, but the involvement of the dopaminergic system in MDMA-induced CPP and reinstatement is poorly understood. Methodology/Principal Findings In this study, the effects of the DA D1 antagonist SCH 23390 (0.125 and 0.250 mg/kg), the DA D2 antagonist Haloperidol (0.1 and 0.2 mg/kg), the D2 antagonist Raclopride (0.3 and 0.6 mg/kg) and the dopamine release inhibitor CGS 10746B (3 and 10 mg/kg) on the acquisition, expression and reinstatement of a CPP induced by 10 mg/kg of MDMA were evaluated in adolescent mice. As expected, MDMA significantly increa…
Effects of risperidone on the acquisition and reinstatement of the conditioned place preference induced by MDMA
2013
Some users of 3,4-methylenedioxymethylamphetamine (MDMA or ecstasy) abuse this drug and/or become concerned about their use. These individuals would benefit greatly from the development of pharmacological strategies to reduce MDMA consumption. We have previously observed that antipsychotics block acquisition and expression of the conditioned place preference (CPP) induced by MDMA, though they do not modify priming-induced reinstatement of MDMA-induced CPP after extinction. In the present study we have evaluated the capacity of the mixed serotonin (5-HT2A)/dopamine (DA D2) antagonist risperidone to block acquisition and reinstatement of MDMA induced-CPP. Adolescent male mice conditioned with…