ACHE and Parkinson disease: Furthermore, comparing PD-fallers vs. PD non-fallers, another group found that acetylcholinesterase levels (indirect markers of cholinergic denervation) at the pedunculopontine nucleus and basal nucleus of Meynert (the two main cerebral cholinergic centers) were significantly lower in the fallers subgroup regardless of the degree of dopaminergic denervation [34].