Cholinergic system choline acetyltransferase

Synthesis of acetylcholine Choline is transported from the extracellular fluid into the cytoplasm of the cholinergic neuron by a carrier system that cotransports sodium and can be inhibited by the drug hemicholinium. Choline acetyltransferase (CAT) catalyzes the reaction of choline with acetyl CoA to form acetylcholine in the cytosol. 

Catalpol. Zhang et al. [233] studied the neuroprotective effects of catalpol, an iridoid glycoside isolated from the fresh rehmannia roots, on the cholinergic system and inflammatory cytokines in the senescent mouse brain induced by D-galactose. Acetylcholinesterase (AChE) activity increased in senescent mouse brain and choline acetyltransferase (ChAT) decreased in the basal forebrain of senescent mouse. Muscarinic acetylcholine receptor Ml (mAChRl) expression declined and the levels of tumor necrosis factor (TNF-a), interleukin-ip (IL-ip), and advanced glycation end products... 

Neuromodulatory transmitter inputs to MOB. Darkfield photomicrographs showing the distribution of cholinergic (a), noradrenergic (b), and serotonergic (c) fibers revealed respectively with immunohistochemistry for choline acetyltransferase (ChAT), dopamine-jS-hydroxylase (DBH), and serotonin (5-HT). Reprinted from Handbook of Chem. Neuroanat. Integrated Sys. CNS, Vol. 12, Part III, Chapter III, The Olfactory System, M. Shipley et al., pp. 469-573, 1996, with permission from Elsevier, Ltd... 

Kimura H, McGeer PL, Peng JH, McGeer EG (1981) The central cholinergic system studied by choline acetyltransferase immunohistochemistry in the cat. J. Comp. Neurol, 200, 151-201. 

In a separate study of 192 IgG-saporin-treated animals, CDD-0102 produced a similar improvement in performance following oral administration (10 mg/kg, p.o.). Rats receiving saline achieved 55 + 4.0% correct while animals receiving CDD-0102 achieved 94 + 1.2% correct. Lesions of the basal forebrain cholinergic system were confirmed by assaying choline acetyltransferase activity following completion of each behavioral study. 

Evidence that acetylcholine is a chemical mediator of synaptic transmission elsewhere in the central nervous system is circumstantial but convincing. Acetylcholine is the transmitter substance from motor nerves, preganglionic autonomic fibres and the postganglionic fibres of the parasympathetic system to their respective effector cells. In all these fibres, the activity of choline acetyltransferase (choline acetylase), the enzyme responsible for the synthesis of acetylcholine, is high. Conversely, its activity is negligibly low in sensory nerve fibres and transmission from these fibres is demonstrably non-cholinergic in nature . It is reasonable, therefore, to... 

We observed increased bromine concentrations in brain regions of AD subjects compared with controls. Br can substitute for Cl. The replacement of Cl by Br seems to have an effect on neurotransmitter function. It has been shown that brominated components of the cholinergic system inhibit the action of choline acetyltransferase, an enzyme known to be affected in AD. 

Biosynthesis of ACh involves a reversible reaction in which an acetyl group is transferred from acetyl coenzyme A to choline by the enzyme choline acetyltransferase. The rate-limiting step in ACh s)mthesis is the availability of choline, which is transported into neuronal terminals from the extracellular space by sodium-dependent, high-affinity uptake systems. ACh s)mthesized in the cytosol is stored in vesicles via the action of the vesicular ACh transporter. In response to an action potential, vesicular ACh is released by exocytosis from cholinergic nerve terminals, where it can interact with two major types of receptors muscarinic... 

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