Mechanisms of Alpha-Synuclein Seeded Aggregation in Neurons Revealed by Fluorescence Lifetime Imaging.

1The brains of Parkinson's disease (PD) patients are characterized by the presence of Lewy body inclusions enriched with fibrillar forms of the presynaptic protein alpha-synuclein (aSyn). Despite related evidence that Lewy pathology spreads across different brain regions as the disease progresses, the underlying mechanism hence the fundamental cause of PD progression is unknown. The propagation of aSyn pathology is thought to potentially occur through the release of aSyn aggregates from diseased neurons, their uptake by neighboring healthy neurons via endocytosis, and subsequent seeding of native aSyn aggregation in the cytosol.

A FRET-Based FLIM Method to Probe Membrane-Induced Alpha-Synuclein Aggregation in Neurons.

1Parkinson's disease (PD) involves the aggregation of the protein alpha-synuclein, a process promoted by interactions with intracellular membranes. To study this phenomenon in neurons for the first time, we developed a fluorescence lifetime imaging (FLIM) method using Förster resonance energy transfer and self-quenching reporters, analyzed with a custom-built FLIM microscope. This method offers insights into aggregate formation in PD and can be broadly applied to probe protein-membrane interactions in neurons.

Site-specific seeding of Lewy pathology induces distinct pre-motor cellular and dendritic vulnerabilities in the cortex.

Circuit-based biomarkers distinguishing the gradual progression of Lewy pathology across synucleinopathies remain unknown. Here, we show that seeding of α-synuclein preformed fibrils in mouse dorsal striatum and motor cortex leads to distinct prodromal-phase cortical dysfunction across months. Our findings reveal that while both seeding sites had increased cortical pathology and hyperexcitability, distinct differences in electrophysiological and cellular ensemble patterns were crucial in distinguishing pathology spread between the two seeding sites.

Developmental neurotoxicity of PFOA exposure on hiPSC-derived cortical neurons.

PFOA is a legacy Per- and Polyfluorinated Substances (PFAS), a group of chemicals widely used in various industrial applications and consumer products. Although there has been a voluntary phase out of PFOA since 2005, it is still widely detected in various water supplies. A growing body of evidence suggests an association between PFOA exposure, particularly during developmental stages, with increased risks of neurodegenerative diseases (NDs).