Tropomyosin distinguishes Lewy bodies of Parkinson disease from other neurofibrillary pathology.

Research into the cellular changes in the degenerative diseases of the central nervous system has focused on the alterations in the constituent proteins of the neuronal cytoskeleton. Although both microtubule and neurofilament proteins have been implicated in the formation of neurofibrillary pathology in Alzheimer, Pick, diffuse Lewy body and Parkinson diseases and progressive supranuclear palsy (PSP), until recently there has been little consideration of whether other cytoskeletal systems are involved. With the findings that epitopes of the microfilament associated protein tropomyosin are present in the neurofibrillary pathology of Alzheimer disease, we decided to investigate the presence of this protein in these related diseases. To address whether the inclusion bodies of other degenerative diseases share this property, sections of brain were immunostained with antibodies to smooth and skeletal muscle tropomyosin. Although neurofibrillary tangles in PSP, Pick bodies and some diffuse Lewy bodies stained, Lewy bodies of idiopathic Parkinson disease did not. This property further distinguishes the Lewy body of Parkinson disease from other neurofibrillary pathologies.