Classification of senile plaques by three-dimensional analysis.

We evaluated the number of each senile plaque subtype in Alzheimer's brain by the usual two-dimensional analysis using a single, methenamine silver stained section and three-dimensional analysis using serial section reconstruction. The number of classic plaques was underestimated due to a lack of precision in the usual evaluating procedures (two-dimensional analysis), while that of stellate deposits was overestimated. From these results, it was suggested that the three-dimensional analysis by gapless serial sections was indispensable to examine and subclassify senile plaques.