In cholinergic neurons, acetylcholine is synthesized from choline and acetyl-coenzyme A (acetyl-CoA). Following depolarization, acetylcholine is released in the synaptic cleft via synaptic vesicles and activates muscarinic and nicotinic receptors located on postsynaptic membranes. Acetylcholine released in the synaptic cleft is rapidly hydrolyzed into choline and acetate. Since choline is not de novo synthesized and thereby only made available through diet uptake, choline is recycled back into the cells in order to regenerate acetylcholine. For this purpose, choline is taken up by the high affinity choline transporter (CHT).