In this study, the ligand-receptor-G protein interactions of the dopamine D3 receptor expressed in Chinese hamster ovary cells were investigated using guanosine 5'-[gamma-thio]triphosphate-[35S] ([35S]GTPgammaS) and receptor binding experiments. Dopamine stimulated the [35S]GTPgammaS binding in a guanine nucleotide, magnesium and sodium-dependent manner. Dopamine and quinpirole produced maximal...

BACKGROUND The relationship between the striatal dopaminergic system and cardiovascular activity is not well known. The aim of this study is to investigate the relationship between striatal D2/D3 receptor binding and cardiovascular activity. METHODS The striatal D2/D3 receptor binding of 34 healthy volunteers was assessed by the single-photon emission computed tomography (SPECT) imaging metho...

OBJECTIVE Dopamine is an endogenous neuromodulator in cortical circuits and the basal ganglia. In animal models of temporal lobe epilepsy (TLE), seizure threshold is modulated to some extent by dopamine, with D1-receptors having a pro- and D2-receptors an anticonvulsant effect. We aimed to extend our previously reported results on decreased D2/D3 receptor binding in the lateral epileptogenic te...

The loss of dopamine neurons observed in Parkinson's disease (PD) elicits severe motor control deficits which are reduced by the use of dopamine agonists. However, recent works have indicated that D3-preferential agonists such as pramipexole can induce impulse control disorders (ICDs) such as food craving or compulsive eating. In the present study, we performed an intermittent daily feeding exp...

This experiment examined the influence of U-99194A, a dopamine D3 receptor antagonist, on ethanol's rewarding effect in a place conditioning paradigm. Swiss-Webster mice received six pairings of a tactile stimulus with ethanol (2 g/kg, i.p.), U-99194A (20 mg/kg, i. p.) with ethanol, or U-99194A alone. A different stimulus was paired with saline. During conditioning, ethanol or ethanol/U-99194A ...

The profile of dopamine receptor subtype activation contributing to the therapeutic efficacy and motor response complications of levodopa (nonselective pro-agonist) in Parkinson's disease remains unclear. Potent, selective, short-acting dopamine D2 receptor subfamily agonists show good antiparkinsonian efficacy but produce dyskinesias comparable to levodopa. Nonetheless, agonists displaying hig...

The D3 dopamine (DA) receptor is a member of the D2-like DA receptor family. While the D2 receptor is abundant especially in motor-regions of the striatum, the D3 receptor shows a relative abundance in limbic regions and globus pallidus. This receptor is of current interest in neurology because of its potential involvement in psychiatric and motor complications in Parkinson’s disease and the po...

Dopamine D3 receptors are preferentially localized in the limbic system and midbrain, and thus may be involved in the pathophysiology of neuropsychiatry disorders. [11C](+)-PHNO is the first preferential D3 receptor radioligand in humans, yet there are no blockade studies with a D3 receptor antagonist in humans. This study characterized the blockade of [11C](+)-PHNO binding by ABT-925, a D3 rec...

Compulsive tanning despite awareness of ultraviolet radiation (UVR) carcinogenicity may represent an "addictive" behavior. Many addictive disorders are associated with alterations in dopamine (D2/D3) receptor binding and dopamine reactivity in the brain's reward pathway. To determine if compulsive tanners exhibited neurobiologic responses similar to other addictive disorders, this study assesse...