BACKGROUND/AIMS Levodopa and dopamine agonists have different effects on the motor, cognitive, and psychiatric aspects of Parkinson's disease (PD). METHODS Using a computational model of basal ganglia (BG) and prefrontal cortex (PFC) dopamine, we provide a theoretical synthesis of the dissociable effects of these dopaminergic medications on brain and cognition. Our model incorporates the find...

Administration of apomorphine and amphetamine induces climbing behavior in mice due to stimulation of brain dopamine receptors. In the present study, the effects of adrenoceptor agonists and antagonists on amphetamine-induced climbing have been investigated. Intraperitoneal (i.p.) injection of different doses of amphetamine (2,4 and 8 mglkg) induced climbing in mice (p<O.OOO 1). The u2- ad...

CONTENTS 1. Introduction 230 2. Concepts of the functional role of striatal dOpaminergic activity 231 2.1. Introduction 231 2.2. The behavioural actions of dopamine in the striatum: unitary or diverse? 231 2.3. Regional differences in the striatal functions revealed by the actions of dopamine 232 2.4. The side to which the striatum's behavioural effects are referred 232 2.4.1. The traditional v...

In Parkinson's disease, one of the most troublesome dilemmas is the treatment of levodopa-induced dyskinesia. After a few years, chronic treatment with levodopa is associated with the development of dyskinesias. Strategies to delay or to reduce dyskinesias are based on the change of levodopa dosing or the early use of dopamine agonists. Dopamine agonists with different pharmacological profile a...

The development of drugs which stimulate selectively the prejunctional dopamine receptor has become a major challenge in recent years1,2), These autoreceptor agonists decrease synthesis and release of dopamine (OA), Thus, the symptoms of schizophrenia originated from dopamine hyperactivity in the mesolimbic system should be reduced. On the other hand, it has been shown that OA autoreceptor agon...

Dopamine agonists are the drugs of choice in the treatment of prolactinomas, the most common type of pituitary adenomas. However, up to 25% of prolactinomas do not respond to these drugs and alternative treatments have to be considered. We describe a 37-year old female with a microprolactinoma who, although having received all available formulations of dopamine agonists over a period of 11 year...

Several dopamine agonists, administered i.m., produced persistent, excessive and non-localized scratching in squirrel monkeys (Saimiri sciureus). Studies were conducted with a series of drugs to determine the pharmacological mechanisms responsible for this effect. All of the dopamine D2 agonists studied produced dose-related increases in scratching, whereas several dopamine D1 receptor agonists...