Noninvasive imaging of amyloid-beta and tau in rodent and nonhuman primate models

Neurodegenerative diseases are characterized by the aberrant accumulation of protein aggregates. The development of noninvasive imaging techniques for detecting pathological hallmarks, amyloid‐beta plaques and tau tangles in Alzheimer's disease patients has advanced significantly and has demonstrated clinical utility in recent years as well as in the research setting. Imaging modalities such as positron emission tomography (PET) are most widely used for studying amyloid‐beta and tau in research as well as in clinical settings with direct translation. PET imaging tracers for primary tauopathies such as progressive supranuclear palsy, corticobasal degeneration (four‐repeat), and Pick's disease (three‐repeat tau) are emerging. Moreover, single‐photon emission computed tomography, optical imaging, and magnetic resonance imaging (MRI) have been pivotal in studying these protein aggregates in the brains of small animals. Optical imaging techniques provide nonionizing radiation, high sensitivity, broad availability, high spatial resolution, and sensitivity, such as aggregation‐induced emission and relatively low cost, making them valuable for preclinical research. This review summarizes the latest advancements in noninvasive imaging of amyloid‐beta and tau in rodent and nonhuman primate models using different imaging modalities (PET, optical imaging, and MRI), with a focus on new findings from the past 5 years.