The source of choline for acetylcholine synthesis in brain

doi:10.1016/0024-3205(76)90285-X

Life Sciences

Volume 19, Issue 7, 1 October 1976, Pages 949-961

https://doi.org/10.1016/0024-3205(76)90285-X Get rights and content

Abstract

More is known about the synthesis and metabolism of acetylcholine (ACh) than other choline (Ch) containing compounds in the brain in spite of the fact that ACh represents only a small fraction of the total Ch esters. This review will attempt to summarize the evidence for the source of Ch in the brain and its relation to the turnover of ACh. Ch is a precursor not only for ACh but also for phosphoryl Ch and phospholipids. It appears that in the rat a bound form of Ch in the brain can produce free Ch which can leave the brain, be converted to ACh or be reutilized for phospholipid synthesis. There is evidence that one of the sources of free Ch that is utilized for ACh synthesis is outside the cholinergic nerve terminal.

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Whether patients with myasthenia gravis (MG) exhibit cognitive impairment is controversial. Also the underlying mechanisms are unknown. We aimed to investigate alterations in cognitive function, neurometabolite levels, and brain function in patients with MG and to explore the associations between abnormal regional brain functional activity, neurometabolite concentrations in the MPFC and left thalamus, and cognitive activity in patients with MG. Neuropsychological tests, proton magnetic resonance spectroscopy, and resting-state functional magnetic resonance imaging were performed on 41 patients with MG and 45 race-, sex-, age-, and education-matched healthy controls (HCs). The results suggest that MG is accompanied by cognitive decline, as indicated by global cognitive function, visual-spatial function, language, memory, abnormalities in regional brain functional activity, and neurometabolite alterations (including GABA, NAA, and Cho) in the medial prefrontal cortex (MPFC) and left thalamus. Cognitive impairment in patients with MG may be related to abnormal regional brain functional activity and changes in neurometabolites, and regional brain functional activity may be modulated by specific neurometabolites.
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Notably, this part of our data are consisted with the hypothesis that MI depletion may be the pathogenesis of diabetic complications [31]. Cho is the precursor for phosphatidylcholine, which is a major constituent of the cell membrane [32,33]. Increased Cho could be related with conditions such as increased membrane turnover or number of cells and myelin breakdown [14].
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As for Cho, an extensive review by Kreis yielded lower Cho in GM (1.35 mM) than WM (1.58 mM), also supported by other studies [1,11,32,38,45–48]. Choline containing compounds are involved in cell membranes lipid metabolism through phospholipids synthesis and cell membranes turn over [5,45,39,49]. Therefore substantially higher Cho in WM can be interpreted as higher membrane lipid contents in WM comprising lipid rich dense myelin sheath which led to higher tCho level [45,50].
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^∗: Presently at College of Pharmacy, University of South Carolina, Columbia, South Carolina 29208, USA.

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MinireviewThe source of choline for acetylcholine synthesis in brain

Abstract

Brain Res.

J. Biol. Chem.

Life Sci.

Life Sci.

J. Nutrition

Biochim. Biophys. Acta

J. Lipid Res.

J. Biol. Chem.

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Biochim. Biophys. Acta

Biochem. Pharmacol.

J. Biol. Chem.

Brain Res.

J. Lipid Res.

Arch. Biochem. Biophys.

Biochem. Biophys. Res. Commun.

J. Biol. Chem.

Biochem. Biophys. Res. Commun.

Brain Res.

Brain Res.

Pharmacologist

J. Neurochem.

Science

Psychopharmacol. Commun.

J. Microwave Power

J. Neurochem.

J. Neurochem.

J. Neurochem.

J. Neurochem.

J. Pharmacol.

Arch. Sci. Physiol.

J. Physiol.

J. Physiol.

J. Neurochem.

J. Pharmacol.

J. Physiol.

J. Neurochem.

J. Physiol.

J. Physiol.

J. Pharmacol.

Res. Commun. Chem. Pathol. Pharmacol.

Arch. int. Pharmacodyn.

J. Physiol.

J. Pharmacol.

Amer. J. Physiol.

Amer. J. Physiol.

J. Neurobiol.

Minireview
The source of choline for acetylcholine synthesis in brain