Presynaptic cholinergic function, such as loss of choline acetyl transferase (ChAT), the enzyme for synthesis of acetylcholine (ACh) from choline and acetyl-coenzyme A, and the vesicular acetylcholine transporter (VAChT), the transporter for the accumulation of acetylcholine (ACh) inside the synaptic vesicles, is changed in AD [26, 27]. Here, CHAT is linked to Alzheimer disease.