In man, non emetic doses of apomorphine elicit a series of behavioural, neurological and psychological changes which are difficult to ascribe to the stimulation of postsynaptic dopamine receptors. Since similar effects are elicited by neuroleptic drugs, the functional changes induced by apomorphine in man might be interpreted as being the result of a decreased dopaminergic activity. The sedatio...

Antipsychotics often lose efficacy in patients despite chronic continuous treatment. Why this occurs is not known. It is known, however, that withdrawal from chronic antipsychotic treatment induces behavioral dopaminergic supersensitivity in animals. How this emerging supersensitivity might interact with ongoing treatment has never been assessed. Therefore, we asked whether dopamine supersensit...

We report the development of a new assay as an alternative to direct DNA sequencing to measure RNA-edited variation in tissue. The new assay has been validated and is accurate, cheaper, more rapid, and less labor-intensive than DNA sequencing. We also outline the statistical modeling required for analyses of the hierarchical, clustered RNA-editing data generated in these studies. Using the new ...

BACKGROUND AND PURPOSE Oromandibular dyskinesia (OMD) can occur spontaneously or they can be induced by the conventional dopamine receptor antagonists. Anticholinergic medications have rarely been reported to cause OMD in parkinsonian or non-parkinsonian patients. METHODS We analyzed the clinical features of two parkinsonian and one non-parkinsonian patients who experienced OMD after antichol...

The purpose of this study was to determine the mechanisms of dopamine regulation of phosphate uptake in opossum kidney (OK) cells, a model of proximal renal tubules. Dopamine stimulated cAMP generation and inhibited radiolabeled phosphate uptake into OK cell monolayers by 14.4 +/- 1.8%. The effect of dopamine was transient, as phosphate uptake returned toward control level by 3 h despite the co...

Prolactin release is a side effect of antipsychotic therapy with dopamine antagonists, observed in rats as well as humans. We examined whether two semimechanistic models could describe prolactin response in rats and subsequently be translated to predict pituitary dopamine D2 receptor occupancy and plasma prolactin concentrations in humans following administration of paliperidone or remoxipride....

How autoreceptors contribute to maintaining a stable output of rhythmically active neuronal circuits is poorly understood. Here, we examine this issue in a dopamine population, spontaneously oscillating hypothalamic rat (TIDA) neurons, that underlie neuroendocrine control of reproduction and neuroleptic side effects. Activation of dopamine receptors of the type 2 family (D2Rs) at the cell-body ...

Previous studies have shown that antidepressant drugs with different pharmacological profiles, administered repeatedly, increase the locomotor hyperactivity induced by various dopaminomimetics, among others by (+/-)7-hydroxydipropylaminotetralin (7-OH-DPAT). Since, according to a recent study, this drug shows a high affinity for not only dopamine D3 but also dopamine D2 receptors, a question ar...

The interaction of dopaminergic antagonists with the D(1A) dopamine receptor was assessed in PC2 cells that transiently express this receptor. The maximal binding and dissociation constants for the D(1A) dopamine receptor, using the ligand [(125)I]SCH23982 were 0.38 +/- 0.09 nM and 1 to 4 pmol/mg, respectively, when assessed 48 h after transfection with cDNA encoding the rat D(1A) receptor. Bas...

We have observed that systemic administration of cannabinoid CB1 antagonists exerts antiparkinsonian effects in rats with very severe nigral lesion (>95% cell loss), but not in rats with less severe lesion (85-95% cell loss). Local injections into denervated striatum and corresponding globus pallidus reduced parkinsonian asymmetry. Infusions into lesioned substantia nigra enhanced motor asymmet...