Figure 3.

Baseline co-dependency of in vivo nicotinic binding sites in the brain and AChE levels in CSF. Positive correlation between the in vivo nicotinic binding sites in the primary visual cortex and AChE activity (A) and the protein levels of the synaptic AChE-S variant (B) in the CSF of the Alzheimer’s disease (AD) patients collected at baseline prior to the galantamine treatment. Panel (C) illustrates the positive correlation between the CSF AChE-S protein and the in vivo ¹¹C-nicotine binding in the whole-brain measured by PET. Here, the values are given as 1−k₂ since k₂* values have an inverse relationship with ¹¹C-nicotine binding, i.e., a low k₂* values mean a higher ¹¹C-nicotine binding level. CSF, cerebrospinal fluid; PET, positron emission tomography; AChE-S, synaptic acetylcholinesterase splice variant proteins.