[PET study of cholinergic system in the brain].

Abstract

Recently, we have developed a method to measure acetylcholinesterase (AChE) activity, a functional marker for cholinergic system, by positron emission tomography (PET) and carbon-11 labeled N-methyl-4-piperidyl acetate. Kinetic analysis of the radioactivity in the brain and the plasma yielded a rate constant "k 3" as an index of AChE activity. The ratios for the k 3 values for the cerebral cortex/thalamus/cerebellum/striatum found in healthy participants were 1/3/8/10, respectively, corresponding well with AChE activity ratios in the brain at necropsy (1/3/8/38), except for the striatum. In 23 healthy volunteers (age range: 24-89 years), there was no age-related decline of k 3 values in the cerebral cortex, suggesting AChE activity is preserved in aged cerebral cortex. In 11 patients with Alzheimer's disease, there was a significant reduction (-24%) of k 3 values in the cerebral cortex and hippocampus, suggesting a loss of ascending cholinergic system from the basal forebrain to the cerebral cortex and hippocampus. In 16 patients with Parkinson's disease, there was a significant reduction (-18%) of k 3 values in the cerebral cortex. In 10 patients with progressive supranuclear palsy, there was a significant reduction (-38%) of k 3 values in the thalamus. This technique is useful for investigating central cholinergic system in neurodegenerative disorders with dementia.

• Authors: H Shinotoh
• Journal: Rinsho shinkeigaku = Clinical neurology (Rinsho Shinkeigaku) Vol. 39 Issue 1 Pg. 33-5 (Jan 1999) ISSN: 0009-918X [Print] Japan
• PMID: 10377794 (Publication Type: Journal Article, Review)

Chemical References

• Biomarkers
• Acetylcholinesterase

Topics

• Acetylcholinesterase (analysis)
• Biomarkers (analysis)
• Brain (diagnostic imaging, enzymology, physiopathology)
• Cholinergic Fibers (physiology)
• Humans
• Neurodegenerative Diseases (diagnostic imaging, physiopathology)
• Tomography, Emission-Computed (methods)