[Pathological mechanisms of Parkinson's disease].

Parkinson's disease (PD) is the second most common neurodegenerative disease. It is associated with the degeneration of dopaminergic neurons in the substantia nigra pars compacta and other areas of the brain. The pathology of PD is characterized by the accumulation of a cytoplasmic fibrillar structure, wherein alpha-synuclein is the major component. Most occurrences of PD were believed to be sporadic and associated with aging and environmental stress. However, there is now strong evidence for genetic inheritance in a small number of families. Although the pathological mechanisms of PD are still largely unknown, we present the major hypotheses and discuss the future directions of studies in this area.