Presenilin-1 expression in Pick's disease

Recent studies have reported that neuronal populations expressing low level s of presenilin-1 (PS-1) display increased vulnerability in late-onset spor adic Alzheimer's disease (AD). To examine whether this phenomenon also occu rs in other neurodegenerative diseases, we performed a quantitative immunoc ytochemical study of PS-1 distribution in the cerebral cortex of Pick's dis ease (PiD) cases and non-demented individuals. In PiD cases, the percentage of PS-1-containing, Pick body (PB)-free neurons was significantly elevated only in cortical areas showing neuronal loss. In these areas, PS-1 levels, measured by immunoblotting, were often higher in PiD compared to non-demen ted cases. Moreover, PS-1 immunoreactivity was significantly reduced in PB- containing neurons. These data suggest that as previously shown in AD, low cellular expression of PS-1 may be associated with increased neuronal loss and cellular degeneration.