Figure 4.

CCEs are observed in multiple AD transgenic mouse models. A, B, Cyclin A (red, arrows) is expressed in the cytoplasm of frontal cortical (A) and hippocampal (B) neurons of the Tg2576 AD transgenic mouse. The neuronal antigen NeuN (green) was used as a marker for neurons. C, D, No expression of PCNA (green) is found in the either cortical or hippocampal neurons of littermate animals from the same genetic background. The red fluorescence is a propidium iodide counterstain. Neuronal nuclei in the APP23 mouse, another AD transgenic mouse model, also exhibited CCEs. E–H, Immunostaining revealed PCNA-positive neurons (arrows) in the frontal cortex (E) and hippocampus (F) in APP23 mice but not in the nontransgenic controls (G, H). Scale bars, 10 μm.