Nicotinic agonists elicit the release of dopamine from striatal synaptosomes by acting on presynaptic nicotinic acetylcholine receptors (nAChRs) on dopamine nerve terminals. Both alpha3beta2* and alpha4beta2 nAChR subtypes (but not alpha7* nAChRs) have been implicated. Here, we compared nAChR-evoked [(3)H]dopamine release from rat striatal synaptosome and slice preparations by using the nicotin...

The catecholamine dopamine is present in both the central nervous system and in the peripheral tissues of molluscs, where it is involved in regulating reproduction. Application of exogenous dopamine to the isolated albumen gland of the freshwater pulmonate snail Helisoma duryi (Wetherby) induces the secretion (release) of perivitelline fluid. The major protein component of the perivitelline flu...

Dopamine uptake inhibitors may provide a means of sustaining endogenous and exogenous striatal dopamine levels in Parkinson's disease, but most are not selective and also inhibit the noradrenaline and 5-hydroxytryptamine (5-HT) transporters. To determine the involvement of the individual monoamine transporters in the production of motor activity, the effect of the nonselective monoamine uptake ...

Antagonism of D2-like dopamine receptors is the putative mechanism underlying the antipsychotic efficacy of psychotropic drugs. Positron emission tomographic studies suggest that the antipsychotic effect of dopamine receptor antagonists occurs within a therapeutic window between 60% and 80% (striatal) D2 receptor occupancy. The incidence of extrapyramidal side effects increases above the 80% th...

CNS Spectr 13:4 April 2008 279 NEW TREND IN PSYCHOPHARMACOLOGY Dopamine (D)2 partial agonists (DPAs) activate D2 receptors in a manner that is less than the full agonist dopamine yet more than full antagonists (eg, most known antipsychotics). Various DPAs span the spectrum between full agonist at one end and antagonists at the other, with the antipsychotic aripiprazole close to the antagonist e...

Parkinson’s disease is a chronic, progressive neurodegenerative disorder that affects more than 1% of individuals older than 60 years. The motor symptoms of Parkinson’s disease are accompanied by a multitude of nonmotor symptoms, which usually predominate in the later stages of the disease and influence patients’ quality of life. Complex, interconnected neuronal systems involving dopamine and o...

We compared the effects of dopamine and norepinephrine on vasopressin (AVP)-stimulated increases in osmotic water permeability (Pf) and cAMP accumulation in the rat inner medullary collecting duct (IMCD). Both dopamine and norepinephrine inhibited AVP-induced Pf and cAMP accumulation in a concentration-dependent manner; however, norepinephrine was approximately 100-fold more potent than dopamin...

Mesolimbic dopamine controls drug and alcohol seeking behavior. Stimulation of dopamine D3 autoreceptor reduces extracellular levels of dopamine. We tested the hypothesis that dopamine D3 receptor (D3R) gene deletion or its pharmacological blockade counteracts alcohol preference and intake in a long-term voluntary ethanol intake paradigm. Mice D3R -/and their wild type (WT) littermates, treated...

Dopamine D(3) receptors have eluded definitive linkage to neurologic and psychiatric disorders since their cloning over 20 years ago. We report a new method that does not employ a radiolabel for simultaneously defining in vivo receptor occupancy of D(3) and D(2) receptors in rat brain after systemic dosing using the tracer epidepride (N-[[(2S)-1-ethylpyrrolidin-2-yl]methyl]-5-iodo-2,3-dimethoxy...