RAT MICROGLIA EXHIBIT INCREASED DENSITY ON ALZHEIMERS PLAQUES IN-VITRO

The relationship of microglia to senile plaques was investigated by cu lturing glial cells derived from neonatal rat brain on cryostat sectio ns of Alzheimer's disease (AD) or control brain. Rat microglia were id entified by their uptake of DiI-acetylated LDL. Plaques were colocaliz ed using Thioflavin-S staining. Although the number of microglia attac hed to AD tissue sections did not differ significantly from the number on control brain tissue, the density of microglia on senile plaques w as significantly greater than on nonsenile plaque areas of the same se ctions. These results suggest that microglia may have a higher affinit y for senile plaques than for nonsenile plaque regions of AD brain tis sue and are consistent with the hypothesis that microglia respond to p laques. (C) 1998 Academic Press.