Parkinson's disease is a progressive neurodegenerative dysfunction characterized by the loss of pigmented dopaminergic neurons of the nigrostriatal system with a consequent dopamine decrease. The reduction of dopamine levels produces neuronal damage, depigmentation of the substantia nigra, and the presence of intracellular inclusions in dopaminergic neurons. Treatments for Parkinson's disease a...

generated interest in their therapeutic potential in schizophrenia. This has been driven, in part, by the recent approval of the dopamine (D2) receptor partial agonist aripiprazole in the USA and Europe. In comparison with conventional and atypical antipsychotics that mediate their therapeutic effects by D2 receptor blockade, aripiprazole has a unique mechanism of action. However, the concept o...

Dopaminergic drugs affect a variety of cognitive processes, but the direction and extent of effects vary across individuals and tasks. Paradoxical effects are observed, by which the same drug causes cognitive enhancing as well as adverse effects. Here, we demonstrate that individual differences in impulsive personality account for the contrasting effects of dopaminergic drugs on working memory ...

202 Introduction Dopamine systems have long been implicated in schizophrenia and its treatment. There is, however, little evidence for a primary abnormality of dopaminergic innervation in the disease, although subtle neuronal deficits, for which there is substantial evidence in the brain in schizophrenia, could conceivably affect dopaminergic neurotransmission in an indirect manner. However, do...

Species differences in physiology and unique active human metabolites contribute to the limited predictive value of preclinical rodent models for many central nervous system (CNS) drugs. In order to explore possible drivers for this translational disconnect, we developed a computer model of a dopaminergic synapse that simulates the competition among three agents and their binding to pre- and po...

The recent depiction of dopamine receptors (DRs) in tumors that cause Cushing's syndrome (CS) has renewed the debate about the dopamine control on pituitary-adrenal axis, and opened interesting new perspectives for medical treatment of CS. The new insights arise from the recent accurate characterization of DR subtypes expression within tumors causing CS, the discovery of new mechanisms, such as...

The best support for the hypothesized involvement of central nervous system dopamine systems in the pathophysiology of schizophrenia is the association between the affinity of neuroleptic drugs for the D2 dopamine receptor and their potency as antipsychotics. Discrepancy between the time course of receptor binding and the development of antipsychotic effects, however, limits this model. Preclin...

Typical antipsychotics have a high affinity for dopamine receptors. It is therefore of interest to investigate such loci in pharmacogenetic studies on psychosis. We investigated the hypothesis that Ser9Gly polymorphism of the DRD3 gene may play a role in the differences in individual response to typical antipsychotics between schizophrenic patients. The sample was composed of 53 good responders...

It is obvious that DA is an important neurotransmitter in vivo. It is involved in a variety of physiological processes such as mental processes, motor function and hormone regulation. In this context, it is quite understandable that a DA D2 receptor antagonist that inhibits the DA D2 receptor regardless of the state of activity of dopaminergic neurotransmission and inhibit the physiological fun...

The mesolimbic dopaminergic reward system is responsible for the negative affective symptomatology of schizophrenia, which may be related to a low dopamine tonus within the ventral striatum. The monetary incentive delay (MID) task can be used to study the response of the ventral striatum to incentive stimuli. We show that activation of the ventral striatum is low in patients with schizophrenia,...