Toxicity of extracellular secreted alpha-synuclein: Its role in nitrosative stress and neurodegeneration

► Oxidative stress evokes oligomerisation and secretion of synuclein (ASN). ► Secreted ASN can be transferred between neurons causing the death of the recipient cells. ► ASN evokes alterations in neurotransmission, mitochondrial dysfunction and oxidative stress. ► Secreted ASN increases the release of other amyloidogenic peptides and interact with them. ► The molecular events activated by secreted ASN lead to inflammation and selective neuronal death.