– a special variant of positron emission tomography (PET – an imaging study) is used to
by administering an aqueous radioactive glucose solution that distributes in the brain.
“Energy metabolism can be recorded indirectly via the distribution of glucose in the brain. Glucose is an energy carrier. It is therefore assumed that where glucose accumulates in the brain, energy demand and consequently brain activity is particularly high,” says Dr. Matthias Brendel, deputy director of the Department of Nuclear Medicine at LMU Klinikum München.
Microglia in Neurodegeneration
It is generally assumed that FDG-PET signal during brain imaging stems predominantly from brain cells -neurons, as they are reported as the largest energy consumers of the brain.
However, the study presents a contrasting view to the existing notion and demonstrates the predominance of the microglia in consuming high sugars at the early stages of neurodegenerative disease.
The team explored 30 patients with dementia – either Alzheimer’s disease or so-called four-repeat tauopathy through laboratory investigations as well as PET studies. It has been further validated through mice studies as well.
These imaging findings may thus help in serving as a biomarker to capture the microglial response to therapeutic interventions of dementia.
“In recent years, it has become evident that microglia play a crucial, protective role in Alzheimer’s and other neurodegenerative diseases. It would be very helpful to be able to monitor the activity of these cells non-invasively, for example their response to drugs. In particular, to determine whether a therapy is working. Our findings suggest that this may be possible by PET,” says Christian Haass, research group leader at DZNE and professor of biochemistry at LMU Munich.