11C-ER176 + 18F-SMBT1

11C-ER176 + 18F-SMBT1 is an investigational combination of two positron emission tomography (PET) radiopharmaceuticals developed by The Methodist Hospital Research Institute for neuroimaging research. 11C-ER176 is a carbon-11-labeled small molecule that targets the 18-kDa Translocator Protein (TSPO), a biomarker for neuroinflammation expressed in both microglia and astrocytes. It is a second-generation TSPO tracer designed to be insensitive to the rs6971 single nucleotide polymorphism, which typically affects tracer binding affinity in humans. 18F-SMBT1 is a fluorine-18-labeled tracer that selectively targets Monoamine Oxidase B (MAO-B), an enzyme upregulated in reactive astrocytes. By combining these two tracers, researchers can use mathematical modeling to differentiate the specific inflammatory contributions of microglia and astrocytes in the living human brain, particularly in the context of Alzheimer's disease and other neurodegenerative conditions.