Acetylcholine/cholinergic system

Acetylcholine Mescaline, in micromolar concentrations, decreases the release of acetylcholine at the neuromuscular junction, with subsequent effects on end-plate potentials and motor function (Ghansah et al. 1993). Whether or not any similar effect occurs on central cholinergic systems has not been investigated. 

Drugs which enhance the activity of the central cholinergic system have been shown to have antimanic effects. Experimental studies have shown that lithium increases acetylcholine synthesis in the cortex, which is... 

Figure 5. Cartoon of a cholinergic synapse showing major steps in the synthesis of acetylcholine. The two major receptor types, the ionotropic nicotinic receptor and the metabotropic muscarinic receptor, are shown (see also Chapter 1). Presynaptic muscarinic (M2) and nicotinic receptors are also depicted. Drugs which have been widely used to manipulate the cholinergic systems, and which are mentioned in the text, include the muscarinic receptor antagonists scopolamine and atropine and the nicotinic receptor agonist nicotine. Anticholinesterases (discussed elsewhere in this volume) include drugs such as physostigmine, rivastigmine, donepezil, and galanthamine.

The parasympathetic system is exclusively a cholinergic system. The neurotransmitter acetylcholine is produced at both pre- and post-ganglionic nerve cells. Acetylcholine is the neurotransmitter at the preganglionic neurons of the sympathetic system also, but the postganglionic sympathetic stimulation is by norepinephrine. 

The normally harmonious music of the aminergic neuronal spheres is contrapuntal to the brain stem cholinergic system, whose modulatory output is generally reciprocal to the aminergic groups and distinctly phasic and burstlike in character (rather than tonic and regular). In fact, the phasic bursts of acetylcholine (ACh) neuronal discharge appear to be strictly and precisely related to eye movement control by the paramedian reticular formation and the oculomotor system. 

The revival of interest in acetylcholine s role in schizophrenic pathogenesis is symmetrical to a new interest in dopamine s role in dream psychosis. Could it be that in both psychoses the coactivation of dopamine and acetylcholine systems is necessary but only sufficient if either the other aminergic systems are in abeyance (dream and depression psychosis) or the dopamine system overpowers the cholinergic system (manic and schizophrenic psychosis) ... 

The relationship between histaminergic and cholinergic systems Effect of H3 antagonists on brain acetylcholine or choline levels in mice... 

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