ULTRASTRUCTURAL ANALYSIS OF BETA-AMYLOID-INDUCED APOPTOSIS IN CULTURED HIPPOCAMPAL-NEURONS

Following treatment with the beta-amyloid (A beta) 25-35 analog, scann ing and transmission electron microscopy were used to investigate the morphological changes in cultured hippocampal neurons during the cours e of degeneration. Ultrastructural analysis revealed focal cell surfac e blebbing and rapid condensation of nuclear chromatin. Changes in cyt oplasmic morphology included prominent vacuole formation, dispersal of polyribosome rosettes and the disappearance of the golgi complex, smo oth endoplasmic reticulum and microtubules with increased cytoplasmic electron density. Mitochondria and limited rough endoplasmic reticulum remained intact throughout the process of cell death. These results p rovide additional evidence suggesting A beta-induced cell death in vit ro occurs via an apoptotic mechanism.