Examination of dopamine-D3 (D3) receptors with positron emission tomography (PET) have been hampered in the past by the lack of a PET ligand with sufficient selectivity for D3 over dopamine-D2 (D2) receptors. The two types co-localize in the brain, with D2 density significantly higher than D3, hence nonselective PET ligands inform on D2, rather than D3 status. [(11)C]-(+)-PHNO is a novel PET li...

The diverse physiological actions of dopamine are mediated by at least five distinct G protein-coupled receptor subtypes. Two D1-like receptor subtypes (D1 and D5) couple to the G protein Gs and activate adenylyl cyclase. The other receptor subtypes belong to the D2-like subfamily (D2, D3, and D4) and are prototypic of G protein-coupled receptors that inhibit adenylyl cyclase and activate K+ ch...

The short and long isoforms of the dopamine D2 receptor (D2S and D2L respectively) are highly expressed in the striatum. Functional D2 receptors activate an intracellular signalling pathway that includes a cAMP-independent route involving Akt/GSK3 (glycogen synthase kinase 3). To investigate the Akt/GSK3 response to the seldom-studied D2S receptor, we established a rat D2S receptor-expressing c...

Based on the observation that antipsychotic medications display antagonist properties at dopamine D2-like receptors, aberrant dopamine signaling has been proposed to underlie psychosis in patients with schizophrenia. Thus, it is not surprising that considerable research has been devoted to understanding the mechanisms involved in the antipsychotic action of these compounds. It is important to n...

The nervous systems affect immune functions by releasing neurohormones and neurotransmitters. A neurotransmitter dopamine signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. The secondary lymphoid tissues are highly innervated by sympathetic nerve fibers that store dopamine at high contents. Lymphocytes also produce dopamine. In this study, we examined ex...

In this study, the influence of dopamine receptor agonists and antagonists on antinociception induced by bac10fen has been examined in the formalin test. The GABA-B agonist bac10fen induced antinociception in both phases of the formalin test in mice. The dopamine receptor agonists SKF 38393 and quinpirole also induced antinociception in both phases of the test. SKF 38393 but not quinpirole ...

Dopamine receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Receptors [373]) are commonly divided into D1-like (D1 and D5) D2-like (D2, D3 D4) families, where endogenous agonist is dopamine.

BACKGROUND Dopamine D2/D3 receptor availability in the striatum has been linked with executive function in healthy individuals, and is below control levels among drug addicts, possibly contributing to diminished executive function in the latter group. This study tested for an association of striatal D2/D3 receptor availability with a measure of executive function among research participants who...

In the light of recent findings, DA-D3 dopamine receptors with an unclear physiological function are present in the cerebellar cortex. Our preliminary results seem to indicate that bilateral injection of 7-OH-DPAT, a DA-D2/D3 receptor agonist (1 and 10 microg/0.5 microl), to lobule 9/10 of rat cerebellar cortex reduces spontaneous locomotor activity (hypolocomotor effects) and induces balance a...

Dextromethorphan is an NMDA receptor antagonist in the glutamatergic system. Currently, there are some reports showing that the glutamatergic NMDA receptor mechanism stimulates dopamine release from several brain regions. This effect may in part modulate the stereotyped behaviors of dopaminergic system. The purpose of the present study was to determine the interaction between the blockade of NM...