Cholinergics related compounds

Phencyclidine (PCP) and the related compound ketamine have a mixture of clinical effects that reflects their complex pharmacology. Although acting on a specific subset of serotonin-type (HT-2) receptors in the forebrain,22 PCP also has affinity for cholinergic, opiate, and dopamine receptors. This may explain PCP s ability to produce subjec-... 

Cholinergic—stimulated by or releasing acetylcholine or a related compound Cholinesterase—enzyme that hydrolyzes acetylcholine into choline and acetic acid and is important in the functioning of the nervous system Chromatid—one of the two spiral filaments making up the chromosome Chromosomes—structures in the cell nucleus that contain DNA Chronic effect—biological change persisting over a major portion of a lifetime... 

The cholinergic blocking agents which mainly include atropine and related alkaloid are obtained from the plant Atropa belladonna (deadly nightshade), Atropa acuminata, Hyoscyamus niger (black henbane) and Datura stramonium (datura) and semisynthetic atropine/hyoscine analogues and synthetic compounds. 

Other approaches that are not related to the cholinergic system that are used to treat learning, memory, and cognitive impairment irrespective of disease type are with so-called nootropics (Schindler et al., 1984). These are compounds without either sedative or stimulatory properties that may positively affect blood flow and metabolism in the brain. They tend to share the ability to protect (rats) against chemically induced disruptions of memory deficits and learned avoidance behavior. Among the promising compounds are several 2-(N-acetamido)-pyrrolidones. 

Many compounds structurally related to nicotine have been tested for activity with the nicotinic cholinergic receptor but. as with the (+)- isomer of nicotine, they generally less activity as agonists, while showing other activities such as blocking the ion channel. Metabolic derivatives of nicotine may account for some of the actions attributed to nicotine, but not necessarily actions at the nicotinic receptor [162]. Nicotine does, indeed, act on other tissues and some of these actions will be cited in other sections of this review. 

Similarly it has been shown that the most potent norditerpenoid alkaloids acting as inhibitors of mammalian and insect cholinergic receptors have the C-l 8 anthranilic acid esterification, characteristic of the Delphinium norditerpenoid alkaloid methyllycaconitine (MLA), structurally-related to aconitine [40-42], MLA also had antifeedant effects against Spodoptera eridania with associated post-ingestive and toxic effects at doses within the effective antifeedant dose range of compound 30 [40], suggesting a similar antifeedant mode of action between MLA/aconitine and the C-20 diterpenoid alkaloids. 

Mentat compound herbal formula used in Ayurvedic tradition to treat age-related memory and cognitive deficits. controlled animal study showed improved cognitive performance in brain-lesioned rats. likely mechanism is improved cholinergic activity. 

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