beta-Amyloid peptides induce degeneration of cultured rat microglia.

Microglia are often associated with senile plaques, a primary pathological hallmark of Alzheimer's disease (AD) that consists largely of insoluble deposits of beta-amyloid (A beta) protein. Synthetic A beta peptides have been shown to induce neurite dystrophy and neuronal death in vitro when the peptides are assembled into aggregates. We now report that assembled A beta peptides induce morphological evidence of degeneration in process-bearing microglia in vitro, as well as metabolic dysfunction in microglial cultures, but a non-assembling scrambled sequence A beta peptide does not.