CHAT and Parkinson disease: In fact, the loss of specific basal forebrain cholinergic input to the cortex is one of the pathogenic hallmarks of Alzheimer’s dementia (Bartus, 2000), with a concomitant decline in cortical choline acetyltransferase (ChAT) activity also being correlated with cognitive dysfunction in different human pathologies (e.g., dementias, Parkinson disease, brain damage; Candy et al., 1983).