FILAMENTOUS NERVE-CELL INCLUSIONS IN NEURODEGENERATIVE DISEASES

Recent work has shown that abnormal filamentous inclusions within some nerve cells is a characteristic shared by Alzheimer's disease, some f rontotemporal dementias, Parkinson's disease, dementia with Lewy bodie s, multiple system atrophy, as well as Huntington's disease and other trinucleotide repeat disorders. This suggests that in each of these di sorders, the affected nerve cells degenerate as a result of these abno rmal inclusions. Except for trinucleotide repeat disorders, the filame nts involved have been shown to consist of either the microtubule-asso ciated protein tau or alpha-synuclein. Over the past year, mutations i n the genes for tau and alpha-synuclein have been identified as the ge netic causes of some familial forms of frontotemporal dementia and Par kinson's disease, respectively. The discovery last year of neuronal in tranuclear inclusions in Huntington's disease and other disorders with expanded glutamine repeats has suggested a unifying mechanism underly ing the pathogenesis of this class of neurodegenerative diseases.