Advertisement

Topics

Dopamine in the hippocampus is cleared by the norepinephrine transporter.

06:00 EDT 15th June 2011 | BioPortfolio

Summary of "Dopamine in the hippocampus is cleared by the norepinephrine transporter."

Abnormal dopaminergic neurotransmission in the hippocampus may be involved in certain aspects of cognitive dysfunction. In the hippocampus, there is little, if any, expression of dopamine transporters (DAT), indicating that the mechanism for dopamine clearance differs from that in the striatum. Here, by means of in-vivo microdialysis in freely moving rats, we tested the hypothesis that the norepinephrine transporter (NET) is involved in dopamine clearance in the hippocampus. We found that systemic administration of the selective NET inhibitor reboxetine (3 mg/kg) and the psychostimulants amphetamine (0.5 mg/kg) and cocaine (10 mg/kg) increased hippocampal dopamine efflux. Local administration of reboxetine (300 μm) produced a large increase in hippocampal dopamine levels that could not be further enhanced by the addition of the NET/DAT inhibitor nomifensine (100 μm). Administration of the specific DAT inhibitor GBR12909 at a concentration (1 mm) that robustly increased dopamine in the nucleus accumbens had a comparably smaller effect in the hippocampus. In line with a minor role of DAT in the hippocampus, we detected very little DAT in this area using ligand binding with radiolabelled RTI-55. Moreover, in contrast to raclopride (100 μm), a dopamine D2-autoreceptor antagonist, local administration of the α2-adrenoceptor antagonist idazoxan (100 μm) increased hippocampal dopamine. Taken together, our data demonstrate an interaction between dopamine and norepinephrine systems in the hippocampus. It is proposed that this interaction originates from a shared uptake mechanism at the NET level.

Affiliation

Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Journal Details

This article was published in the following journal.

Name: The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychoph
ISSN: 1469-5111
Pages: 1-10

Links

DeepDyve research library

PubMed Articles [2207 Associated PubMed Articles listed on BioPortfolio]

Mechanistic evaluation of Tapentadol in reducing the pain perception using in-vivo brain and spinal cord microdialysis in rats.

Role of monoamine neurotransmitters in the modulation of emotional and pain processing in spinal cord and brain regions is not well known. Tapentadol, a norepinephrine reuptake inhibitor with µ-opioi...

Scaffold Repurposing of Nucleosides (Adenosine Receptor Agonists): Enhanced Activity at the Human Dopamine and Norepinephrine Sodium Symporters.

We have repurposed (N)-methanocarba adenosine derivatives (A3 adenosine receptor (AR) agonists) to enhance radioligand binding allosterically at the human dopamine (DA) transporter (DAT) and inhibit D...

Analytical characterization and pharmacological evaluation of the new psychoactive substance 4-fluoromethylphenidate (4 F-MPH) and differentiation between the (±)-threo- and (±)-erythro- diastereomers.

Misuse of (±)-threo-methylphenidate (methyl-2-phenyl-2-(piperidin-2-yl)acetate; Ritalin®, MPH) has long been acknowledged, but the appearance of MPH analogs in the form of 'research chemicals' has o...

Metformin increases norepinephrine transporter expression in placenta of patients with polycystic ovary syndrome.

To evaluate the norepinephrine (NE) and placental NE transporter (NET) in women with polycystic ovary syndrome (PCOS) non-treated and treated with metformin during pregnancy.

Dopamine transporter imaging does not predict the number of nigral neurons in Parkinson disease.

To examine possible associations between in vivo brain dopamine transporter SPECT imaging and substantia nigra pars compacta (SNc) neuronal survival in Parkinson disease (PD).

Clinical Trials [1198 Associated Clinical Trials listed on BioPortfolio]

Dopamine and Norepinephrine in Shock Patients

The purpose of this study is to compare the efficacy of dopamine and norepinephrine, two commonly used vasopressor agents, in the treatment of shock.

Molecular Imaging of Norepinephrine Transporter (NET) Using [C-11]Methylreboxetine PET in Multiple Sclerosis

This study aims to use [C-11]MRB PET (positron emission tomography) imaging to look at brain injury in patients with Multiple Sclerosis (MS) and healthy individuals. The overarching hypoth...

Brain Dopamine Function in Adults With ADHD

The purpose of the study is to investigate the functional state of dopamine cells and the dopamine transporter in ADHD subjects and controls to assess the effects of chronic methylphenidat...

Dopamine Versus Norepinephrine for the Treatment of Vasopressor Dependent Septic Shock

We are performing a prospective, randomized, controlled trial of dopamine versus norepinephrine for septic shock. The trial will enroll patients with suspected or documented site of infect...

Pharmacogenetic Study of Methylphenidate in Attention Deficit/Hyperactivity Disorder(ADHD)

The noradrenergic system plays a known role in attentional systems and suspected causal role in attention deficit/hyperactivity disorder(ADHD).Methylphenidate also has been suspected as a ...

Medical and Biotech [MESH] Definitions

One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.

A picolinic acid derivative isolated from various Fusarium species. It has been proposed for a variety of therapeutic applications but is primarily used as a research tool. Its mechanisms of action are poorly understood. It probably inhibits DOPAMINE BETA-HYDROXYLASE, the enzyme that converts dopamine to norepinephrine. It may also have other actions, including the inhibition of cell proliferation and DNA synthesis.

A subsection of the hippocampus, described by Lorente de No, that is located between the HIPPOCAMPUS CA1 FIELD and the HIPPOCAMPUS CA3 FIELD.

An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.

The N-demethylated derivative of the antipsychotic agent LOXAPINE that works by blocking the reuptake of norepinephrine, serotonin, or both. It also blocks dopamine receptors.

Quick Search
Advertisement
 


DeepDyve research library

Relevant Topic

Urology
Benign Prostatic Hyperplasia (BPH) Erectile Dysfunction Urology Urology is the branch of medicine concerned with the urinary tract and diseases that affect it. Examples include urethritis, urethrostenosis and incontinence. Urology is a su...


Searches Linking to this Article