PET imaging of acetylcholinesterase

Abstract

Acetylcholinesterase (AChE) is an enzyme that hydrolyzes acetylcholine and thereby regulates the concentration of the transmitter at the cholinergic synapse. AChE is frequently described as a marker of cholinergic neurons in the brain. Several cholinesterase inhibitors have been labeled with carbon-11 as radiotracers for visualizing AChE-binding sites. Among these, carbon-11-labeled methyl-4-piperidyl acetate (MP4A) and methyl-4-piperidyl propionate (MP4P or PMP) are successfully in clinical use for in vivo measurement of AChE activity. Both [11C]MP4A and [11C]PMP opened a window on cerebral cholinergic function in the human brain and have elucidated the role of cholinergic system in Alzheimer's disease, Parkinson's disease, and related disorders.