CHAT and Alzheimer disease: The loss in cholinergic transmission could be correlated to the upstream disruption in the enzyme choline acetyltransferase (ChAT) which is responsible for synthesizing ACh, and the vesicular acetylcholine transporter (VAChT) uptakes the neurotransmitter into synaptic vesicles, which are involved in AD pathogenesis (Davies and Maloney 1976; Ozturk et al. 2006) and should be considered in future investigations.