A time course and dose-response study of the regulation of brain nicotinic receptors by dietary choline

We have previously demonstrated that the administration of oral choline chloride to rats results in a significant increase in the concentration of putative nicotinic cholinergic receptors (nAChRs), as measured by α-bungarotoxin binding, in comparison with rats fed a choline-free diet. We have extended and elucidated these data in the studies reported here. The increase in the concentration of nAChRs was found to be dose-dependent and attributable to choline supplementation rather than choline deficiency. The increase in the concentration of nAChRs occurs rapidly (within 24 h) and is reversible (over a period of days) upon elimination of choline supplementation. The oral administration of choline chloride has been successful in some but not all neurological disorders associated with presumed cholinergic hypoactivity. Studies of dietary choline intake in animals may provide information with respect to the mechanism by which choline stimulates an increase in nAChRs and may suggest a treatment regime that maximizes the central effects of choline.