Ultrastructural analysis of beta-amyloid-induced apoptosis in cultured hippocampal neurons.

Following treatment with the beta-amyloid (A beta) 25-35 analog, scanning and transmission electron microscopy were used to investigate the morphological changes in cultured hippocampal neurons during the course of degeneration. Ultrastructural analysis revealed focal cell surface blebbing and rapid condensation of nuclear chromatin. Changes in cytoplasmic morphology included prominent vacuole formation, dispersal of polyribosome rosettes and the disappearance of the golgi complex, smooth 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 provide additional evidence suggesting A beta-induced cell death in vitro occurs via an apoptotic mechanism.