Novel in situ seeding immunodetection assay uncovers neuronal-driven alpha-synuclein seeding in Parkinson's disease.

Aggregates of alpha-synuclein (α-syn) propagate through template-induced misfolding in people with Parkinson's disease (PD) and Multiple System Atrophy (MSA). Prion-like seeding is crucial in disease initiation and progression, representing a major target for disease-modifying therapies. The detection of α-syn seeding with seeding amplification assays (SAAs) has remarkable diagnostic and research potential.

Seeding-competent early tau multimers are associated with cell type-specific transcriptional signatures.

The initial molecular alterations of Alzheimer's disease (AD) are unknown. Established AD is characterized by profound structural and transcriptional alterations in the human brain, with the hallmark neuropathological features being beta-amyloid (Aβ) accumulation in senile plaques and hyperphosphorylated fibrillar tau in neurofibrillary tangles (NFTs). Previous evidence indicates that tau multimerization into small aggregates is one of the earliest molecular alterations, anticipating the accumulation of hyperphosphorylated tau in NFTs.

Neuropathological stages of neuronal, astrocytic and oligodendrocytic alpha-synuclein pathology in Parkinson's disease.

Alpha-synucleinopathies are neurodegenerative diseases characterized by the spread of alpha-synuclein (α-syn) aggregates throughout the central nervous system in a stereotypical manner. These diseases include Lewy body disease (LBD), which encompass Dementia with Lewy bodies (DLB), Parkinson's Disease (PD), and Parkinson's Disease Dementia (PDD), and Multiple System Atrophy (MSA). LBD and MSA chiefly contain α-syn aggregates in neurons and oligodendrocytes, respectively, although glial α-syn pathology in LBD is increasingly being recognized.