Dopaminergic, definition

In summary, however, we do not have a sufficient amount of consistent electrophysiologic data to draw any definitive conclusions concerning the effects of hallucinogenic drugs on either noradrenergic or dopaminergic neurons. 

Clear abnormalities of the dopamine system have not been identified in the periphery or the brain of OCD patients. Nevertheless, repetitive stereotypies and OCD-like behaviors can be produced in humans by the administration of exogenous D2 agonist or stimulants, which suggests that the dopaminergic system may be involved in some way in OCD. Conversely, antipsy-chotics can be used adjunctively in the treatment of selective serotonin reuptake inhibitor (SSRl)-resistant OCD patients with a definite benefit in a significant proportion of patients. 

In addition to acute and chronic schizophrenia, the neuroleptics are sometimes used in the management of mania, delirium, and severe agitation, whatever the cause of these symptom complexes. It must be noted that unlike parkinsonism, where a definite dysfunction in the DA system has been established, for schizophrenia and other psychiatric diseases, no unequivocal evidence has yet been presented to prove that there is a disturbance of the DA system (e.g., dopaminergic overactivity or receptor hypersensitivity). In untreated schizophrenics the production of DA metabolites is normal. Conflicting results have been obtained in studies of the DA receptors in schizophrenics (11,12,13), but in the case of patients who have not received neuroleptics, the receptor density and affinity appear to be normal (13). The "dopamine hypothesis" in these disorders derives from the beneficial effects of drugs that block DA receptors. 

In order to discuss the organization of dopaminergic pathways, an overview of basal ganglia components and circuits is first presented. These circuits form the system that was traditionally defined as extrapyramidal and is now indicated with the more straightforward definition of basal ganglia . 

While the source of dopaminergic input to PC is unclear, in situ and immunocytochem-ical studies have found the presence of D, receptors in layer II of PC (Mansour et al. 1990 Fremeau et al. 1991 Huang et al. 1992). Little is known, though, about the significance of these receptors to PC physiology. To date, there is little definitive evidence concerning the presence of D, receptors in PC. 

Another way to view similarity between 3-D structures is to focus on the pharmacophore atoms and the direction, or points, of their interaction with a target protein. The program FAMILY (142) assigns 3-D structures to families of compounds in which the variation in all distances between the points of interest are within a specified tolerance, usually 0.3-0.5 A. FAMILY uses the Bron-Kerbosh clique detection algorithm (143,144) to find these common 3-D substructures, and is rapid in execution since a typical test found that 384 compounds could be matched over seven points in under a minute on a VAX 9000. The points that are considered in the analysis are selected in an initial run of ALADDIN, and are typically the pharmacophore atoms and all heavy atoms that are attached to them. In a classification of dopaminergics, the atoms attached to these attached atoms were also used to increase the number of families found. In this example of compounds that met the pharmacophore requirements, it was shown that the set of computer-designed compounds (97) sorted itself into 36 families whereas compounds in a definitive review (145) sorted themselves into 15 families. 

Compounds (27) and (28) have shown dopaminergic activity in rats, but to a lower extent than ( - )-apomorphine. Glaucine shows definite anti-tussive activity," and its tetrahydroxy-derivative exhibits anti-thrombic action. ... 

---