Region-specific stability of dendritic extent in normal human aging and regression in Alzheimer's disease. II. Subiculum.

The dendritic trees of pyramidal neurons of layer III or the external pyramidal layer of the subiculum have been studied in Golgi Cox-stained human tissue obtained at autopsy. Fifteen cases were neurologically and psychiatrically normal and ranged in age from 43 to 95 years; and 5 cases had clinically and neuropathologically defined Alzheimer's disease (AD). Measures of dendritic extent did not change in normal aging in either the apical or basal trees. In AD there was a significant reduction in dendritic extent of the apical trees and a non-significant reduction in extent of the basal trees. These alterations of the dendritic trees in AD are consistent with the findings of severe pathology in the subiculum reported by others. Changes in AD were mainly a reduction in numbers of segments, rather than in the lengths of segments.