CHAT and Alzheimer disease: We previously reported a reduction of the acetylcholine-synthesizing enzyme choline acetyltransferase (ChAT), which is a marker of cholinergic neurons, in the post-mortem basal forebrain of individuals with AUD (Vetreno et al., 2014), and degeneration of cholinergic neurons within this region is a hallmark feature of AD (Nagai et al., 1983; McGeer et al., 1984; Lehericy et al., 1993).