Various hormonal and monoaminergic systems play determinant roles in the regulation of several cytochromes P450 (P450s) in the liver. Growth hormone (GH), prolactin, and insulin are involved in P450 regulation, and their release is under dopaminergic control. This study focused on the role of D₂-dopaminergic systems in the regulation of the major drug-metabolizing P450s, i.e., CYP3A, CYP2C, and...

Investigations aimed to define the components of the cholinergic network in the cerebral cortex and their functional modifications under the effect of a number of psychotropic drugs are described. By measuring acetylcholine levels and acetylcholine output from the cerebral cortex in cats and rats with various subcortical lesions, at least two systems of cholinergic neurons ascending to the cort...

Levodopa is the most potent dopaminergic oral drug available in clinical practice. After chronic treatment, many patients with Parkinson's disease develop dyskinesia and motor fluctuations which are difficult to manage. It was hoped that introduction of dopaminergic agonists could diminish these side effects while keeping the same efficacy as levodopa. Prospective clinical data do not support t...

The role of dopaminergic and cholinergic functions in the genesis of an electroretinogram is unclear. The present study was carried out to elucidate the direct actions of some psychotropic drugs in isolated rabbit retinas. Methamphetamine and apomorphine decreased dose-dependently the b-wave amplitude at a dose of 10(-7)-10(-5) g/ml. On the other hand, chlorpromazine and haloperidol, as well as...

Degeneration of the dopaminergic system in Parkinson's disease and longstanding exposure to dopaminergic drugs may cause reward system malfunction. This may manifest as addiction to l-dopa and behavioral disturbances associated with the impulse control system. These disturbances include: gambling, excessive spending (shopping), hypersexuality and binge eating. We included one such patient's per...

Changes in dopaminergic function can be regulated by receptor-receptor interaction, or interaction with other proteins with dopamine receptors, and/or elements of the downstream signaling cascades. The complexity of dopaminergic signaling is far from being completely elucidated. It could, however, hold the key to the comprehension of the pathophysiology of neurological and psychiatric disorders...

The last decade brought a considerable progress in pharmacotherapy of addiction. Basing on recently gained knowledge of mechanisms of development of addiction and the physiology of the brain reward system, several therapeutic strategies have evolved. The strategies aimed at targeting the basic mechanisms of addiction rely on the premises that addiction is caused by adaptive changes in the centr...

Natural rewards and drugs of abuse can alter dopamine signaling, and ventral tegmental area (VTA) dopaminergic neurons are known to fire action potentials tonically or phasically under different behavioral conditions. However, without technology to control specific neurons with appropriate temporal precision in freely behaving mammals, the causal role of these action potential patterns in drivi...

According to last findings, one of the most commonly studied polymorphisms in psychiatry-Taq1A is located in the ANNK1 (Ankyrin Repeat and Kinase Domain containing 1) gene, not in the dopamine receptor 2 (DRD2) gene. This polymorphism has been extensively studied in relation to alcohol, nicotine and drugs addiction, eating disorders, ADHD, schizophrenia and pharmacogenetics. The ANKK1 gene cont...

Dear Editor, The role of neurotransmitters other than serotonin in phobicavoidance disorders has been clarified as neural science progresses. Among those, dopamine, both directly and by its interactions with other systems, is an excellent candidate for investigation. In agreement with the author’s hypothesis are also some important clinical correlates of the development of phobias and lack of m...