The dopamine hypothesis of schizophrenia proposes that hyperactivity of dopaminergic transmission is associated with this illness, but direct observation of abnormalities of dopamine function in schizophrenia has remained elusive. We used a newly developed single photon emission computerized tomography method to measure amphetamine-induced dopamine release in the striatum of fifteen patients wi...

Receptor-specific compounds were applied by retrograde microdialysis to the ventral tegmental area (VTA) of the rat brain. The effect of the intrategmental infusions on extracellular dopamine in the ipsilateral nucleus accumbens were recorded with a second microdialysis probe. Intrategmental infusion of muscimol (10-40 microM) or baclofen (50 microM) decreased extracellular dopamine in the nucl...

Spatial learning has been recognized over the years to be under the control of the hippocampus and related temporal lobe structures. Hippocampal damage often causes severe impairments in the ability to learn and remember a location in space defined by distal visual cues. Such cognitive disabilities are found in Parkinsonian patients. We recently investigated the role of dopamine in navigation i...

Based on the well known biological versatility of the imidazoline nucleus, we prepared the novel derivatives 3a-k inspired by 2-BFI scaffold to assess imidazoline molecules as D(2)-like dopamine receptor ligands. Conservative chemical modifications of the lead structure, such as the introduction of an hydroxy group in the aromatic ring alone or associated with N-benzyl substitution, provided pa...

The patch-clamp technique in combination with a fast liquid filament application system was used to study the effect of dopamine on the glutamate receptor desensitization in horizontal cells of the perch (Perca fluviatilis). Kinetics of ligand-gated ion channels in fish horizontal cells are modulated by dopamine. This modulation is presumably mediated by a cAMP-dependent protein phosphorylation...

Experimentally induced and parkinsonian disruptions in dopamine (DA) transmission are associated with motor abnormalities that include a reduced likelihood of behavioral response initiation and an increased duration of executed responses. Here we investigated the dopamine receptor subtypes involved in regulating these two aspects of behavior. We examined the effects of D1 family (D1/D5) antagon...

(1) The present study was performed to assess the effects exerted by the cannabinoid (CB) agonist, (-)11-hydroxy-delta8-tetrahydrocannabinol-dymethylheptyl (HU 210; 12.5-50 microg/kg ip), on rodent behavioural tests involving dopamine (DA) transmission; in comparison, the DA D2 antagonist, S(-)-3-chloro-5-ethyl-N-[(1-ethyl-2-pyrrolidinyl)methyl]-6-hydroxy-2-methoxy-benzamide hydrochloride ((-)e...

Nine compounds are studied for antioxidant activity, including those from the class of catecholamines containing 3,4-hydroxyphenyl (catechol) as a common structural fragment, which imparts properties to in reactions hydrocarbon substrate oxidation. The antiradical activity is determined by chemiluminescent method interception peroxyl radicals model reaction initiated oxidation ethylbenzene (RH)...

we have shown that buspirone, a partial agonist of 5-hydroxytryptamine 1a (5-ht1a) receptors, improves motor dysfunctions induced by 6-hydroxydopamine (6-ohda) and haloperidol in rats. the present work extends these findings by investigating the role of 5-ht1a receptors on catalepsy-like immobilization in rats, a model of parkinson’s disease. catalepsy was induced by unilateral infusion of 6-oh...