PET imaging was used with the tau tracer [<sup>18</sup>F]THK5317 and the MAO-B tracer [<sup>11</sup>C]DED in five patients with Alzheimer's disease to investigate the MAO-B binding component of this first generation tau tracer in vivo.
[<sup>11</sup>C]Deuterodeprenyl ([<sup>11</sup>C]DED) is a tracer that has been used for reactive astrocyte detection in Alzheimer's disease, Creutzfeldt-Jakob disease and amyotrophic lateral sclerosis, among others, with some limitations.
The aim of this study was to investigate how in vivo quantification of astrogliosis using positron emission tomography (PET) radioligand deuterium-L-[<sup>11</sup>C]deprenyl ([<sup>11</sup>C]DED), binding to enzyme monoamine oxidase-B (MAO-B) which is overexpressed in reactive astrocytes during AD, corresponds to expression of glial fibrillary acidic protein (GFAP) and vimentin, i.e., two well-established markers of astrogliosis, during Aβ pathology progression.