Full length alpha-synuclein is present in cerebrospinal fluid from Parkinson's disease and normal subjects

Several clues suggest that alpha-synuclein, a presynaptic protein, plays a central role in the pathogenesis of idiopathic Parkinson's disease (PD). To search a peripheral marker of PD, we analyzed presence and amount of alpha -synuclein in CSF from 12 PD patients and 10 neurologically normal subjects . The protein was extracted from CSF samples through immunoprecipitation an d immunoblotting with different specific anti-alpha-synuclein antibodies. W e identified a 19 kDa band that corresponds to monomeric alpha-synuclein, g iven its comigration with homologue human recombinant peptide as well as wi th the protein extracted from cerebral cortex of normal subjects. The amoun t of CSF 19 kDa alpha-synuclein did not significantly vary in PD and normal cases. These findings have two implications: (a) full length alpha-synucle in is released by neurons in the extracellular space; (b) alpha-synuclein d oes not appear a peripheral marker of PD pathology. (C) 2000 Elsevier Scien ce Ireland Ltd. All rights reserved.