MICROTUBULE-ASSOCIATED PROTEIN-5 IS A COMPONENT OF LEWY BODIES AND LEWY NEURITES IN THE BRAIN-STEM AND FOREBRAIN REGIONS AFFECTED IN PARKINSONS-DISEASE

Ubiquitin-positive Lewy neurites and Lewy bodies are found in idiopath ic Parkinson's disease (PD) and diffuse Lewy body disease (DLBD). We f ound that, in three patients with PD and one with DLBD, microtubule-as sociated protein 5 (MAP5) immunostaining was consistently present in b oth Lewy neurites and Lewy bodies throughout the brainstem and forebra in regions affected in the disease. In contrast, other cytoskeletal ma rkers (neurofilaments and MAP2) could be demonstrated in only a small fraction of Lewy bodies and neurites. Confocal microscopy demonstrated that MAPS immunolabeling was located around the perimeter of the ubiq uitin-positive labeling which occupied the central region of the neuri te and Lewy body, with some overlap between MAPS and ubiquitin stainin g. In contrast, in those Lewy bodies and neurites immunopositive for p hosphorylated and non-phosphorylated neurofilament proteins, the neuro filament labeling was quite peripheral to the ubiquitin staining, with little or no overlap. Our results suggest MAPS is more closely associ ated with the ubiquitinated proteins of Lewy bodies and neurites than other cytoskeletal proteins.