alpha-synuclein is developmentally expressed in cultured rat brain oligodendrocytes

Although a neuronal protein, alpha-synuclein is a major component of glial cytoplasmic inclusions (GCIs) in oligodendrocytes of multiple system atroph y (MSA) brains. Because alpha-synuclein has not been identified in oligoden drocytes of normal brains, we examined cultured rat brain oligodendrocytes during in vitro development and showed that alpha-synuclein mRNA and protei n are present in cultured oligodendrocytes. The expression of alpha-synucle in was developmentally regulated; it increased to peak levels at 2 or 3 day s in culture but declined thereafter. Indirect immunofluorescence further s hows that alpha-synuclein was localized predominantly in cell bodies and pr imary processes of oligodendroglia. Thus, GCIs may be a consequence of alte red rather than de novo expression of alpha-synuclein in MSA oligodendrocyt es. (C) 2000 Wiley-Liss, Inc.