However, Tg mice carrying other APPswe/PS1dE9 or double-mutated tau displayed a marked decrease in several cholinergic biomarkers, including ChAT activity, ACh synthesis, levels of M2 autoreceptors and vesicular ACh transporter, as well as a reduction in the density of ChAT immunopositive neurons in the cortex and hippocampus accompanied by cognitive deficits [87,90]. Here, CHAT is linked to Cognitive impairment.