Clinical and Pre-Clinical Evidence for Enteric α-Synuclein Involvement in Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease, presenting with the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and motor symptoms. Categorized as a synucleinopathy, the pathological hallmark of PD is intracellular filamentous Lewy bodies (LB), which are formed from protopathic aggregates. The most prevalent of these proteins is the presynaptic protein α-synuclein (α-syn). While commonly attributed to neuronal death in SNpc, postmortem studies have shown α-syn immunoreactivity and LB pathology in the peripheral, central, and enteric nervous system (ENS).