The synuclein family includes alpha-Synuclein, beta-Synuclein, gamma-Synuclein, and synoretin. These small, highly conserved proteins are localized predominantly in the brain, concentrated in presynaptic nerve terminals. Alpha-Synuclein is normally a soluble protein. Abnormal alpha-synuclein forms filamentous inclusions (Lewy bodies and Lewy neurites) in several neurodegenerative diseases, including Parkinson's disease (PD), dementia with Lewy bodies, and Alzheimer's disease. Beta-Synuclein and gamma-Synuclein (synoretin) associate with alpha-synuclein and inhibit its aggregation.