Intracerebral inoculation of pathological α-synuclein initiates a rapidly progressive neurodegenerative α-synucleinopathy in mice

The accumulation of misfolded proteins is a fundamental pathogenic process in neurodegenerative diseases. However, the factors that trigger aggregation of α-Synuclein (α-Syn), the principal component of the intraneuronal inclusions known as Lewy bodies (LBs), and Lewy neurites (LNs), which characterize Parkinson's disease (PD) and dementia with LBs (DLB), are poorly understood. We show here that in young asymptomatic α-Syn transgenic (Tg) mice, intracerebral injections of brain homogenates derived from older Tg mice exhibiting α-Syn pathology accelerate both the formation of intracellular LB/LN-like inclusions and the onset of neurological symptoms in recipient animals. Pathological α-Syn propagated along…