Abstract

Deposition of -synuclein fibrils is implicated in Parkinsons disease (PD) and dementia with Lewy bodies (DLB), while in vivo detection of -synuclein pathologies in these illnesses has been challenging. Here, we have developed a small-molecule ligand, C05-05, for visualizing -synuclein deposits in the brains of living subjects. In vivo optical and positron emission tomography (PET) imaging of mouse and marmoset models demonstrated that C05-05 captured a dynamic propagation of fibrillogenesis along neural pathways followed by disruptions of these structures. High-affinity binding of 18F-C05-05 to -synuclein aggregates in human brain tissues was also proven by in vitro assays. Notably, PET-detectable 18F-C05-05 signals were intensified in the midbrains of PD and DLB patients as compared to healthy controls, providing the first demonstration of visualizing -synuclein pathologies in these illnesses. Collectively, we propose a new imaging technology offering neuropathology-based translational assessments of PD and allied disorders towards diagnostic and therapeutic research and development.