Fig. 2.
Aβ toxicity manifests the hallmarks of apoptosis. Cortical neuron preparations were treated with medium change alone (A, B) or Aβ1–40 (40 μm, lot ZM482) for 24 hr (C, D) and then assessed for chromatin integrity as discerned by Hoechst 33258 staining (A, C) and by DNA end labeling (B, D). The incidence of neurons manifesting punctate and fragmented chromatin is much higher in Aβ-treated neurons; note that neurons that manifest punctate chromatin also display an increased amount of fragmented DNA, as assessed by DNA end labeling.