CELL LOSS IN THE NUCLEUS BASALIS IS RELATED TO REGIONAL CORTICAL ATROPHY IN ALZHEIMERS-DISEASE

Cortical atrophy and cell loss in the cholinergic nucleus basalis is a well-established characteristic of Alzheimer's disease; however, prev ious studies not have analysed cholinergic cell loss and cortical atro phy in concert. In autopsy brains from eight patients with Alzheimer's disease and 12 control subjects, the numbers of nucleus basalis neuro ns were determined from 50-mu m serial Nissi-stained sections. Volumes of the cerebrum, cortical gray matter (total, lobar and subregional), white matter and deep gray structures were computed by point counting on black and white photographs of gapless 3-mm coronal slices of form alin-fixed brains. Cell loss in the nucleus basalis was found to range between 89% and 42% in Alzheimer's disease compared with controls. Wh ite matter volume was unchanged in absolute terms in Alzheimer's disea se patients compared with controls, while cortical volume was signific antly reduced. Gray matter atrophy was most prominent in temporal and frontal cortices. A highly significant linear relationship was found b etween cortical volume and nucleus basalis cell number in controls and Alzheimer's disease patients, with values fbr both groups on a single regression line. Whole brain and cerebral volumes were also highly co rrelated to nucleus basalis cell numbers in both groups. A quantitativ e analysis of plaque and tangle burden in cortical target areas of the nucleus basalis was performed. In contrast to the relationship with c ortical volume, nucleus basalis cell number and neurofibrillary tangle number were not significantly correlated to the density of cortical h istopathology. These results suggest that the volume of cortical gray matter is coupled to the number of nucleus basalis neurons. Compromise d viability of nucleus basalis neurons may precede cortical volume los s as large numbers of neurofibrillary tangles, detected with nickel pe roxidase staining, were found in this nucleus in all Alzheimer's disea se cases, including those with minimal cell loss. (C) 1997 IBRO.