Argyrophilic glial inclusions in the midbrain of patients with Parkinson'sdisease and diffuse Lewy body disease are immunopositive for NACP/alpha-synuclein

Argyrophilic glial inclusions occur in the midbrain of patients with Parkin son's disease (PD) and diffuse Lewy body disease (DLBD). These inclusions a re immunohistochemically positive for NACP/alpha-synuclein but negative for tau protein. The results of the present study suggest that a primary degen erative process involves NACP/alpha-synuclein in PD and DLBD and that the p rocess takes place not only in neurons but also in glial cells. Argyrophili c cytoplasmic inclusions, both glial and neuronal, in a variety of degenera tive diseases may be grouped into two major categories; one related to aggr egates of abnormally phosphorylated tau protein and the other to unusual ac cumulations of NACP/alpha-synuclein. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.