Abstract: Neurodegenerative disease is characterized by the presence of inclusion bodies containing abnormal toxic proteins in the central nervous system. Physiological α-synuclein exists in the form of a monomer or dimer at the presynaptic nerve terminal. It serves as a key molecule to modulate endocytosis and exocytosis. However, under pathological conditions, α-synuclein adopts different conformations, being converted into toxic oligomers. The molecular weight of α-synuclein oligomers ranges from 25 to 180 kDa, and they do not form filamentous aggregates of α-synuclein. Subsequently, α-synuclein oligomers change to aggregates, including protofibrils and fibrils (Miki et al., 2022). This process has been implicated in the pathogenesis of neurodegenerative diseases collectively termed synucleinopathies, which include Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy (MSA).