Paracrystalline structure of mouse model Hirano Bodies. Hemisphere brain was dissected by separating hippocampus from cortex and thalamus. (A, B) Transmission electron microscope (TEM) images of the electron dense region in CT-GFP stable H4 human neuroglioma cells show the composition, filamentous organization, and cross-hatched appearance of the inclusions. (C-J) TEM images of hippocampus in homozygous double transgenic mice at 6 months reveal model Hirano bodies with characteristic structure and periodicity. The small size of filamentous inclusions are enclosed by myelin sheath and resemble the ultrastructural definition of Hirano bodies reported in the hippocampus of an Alzheimer's patient. Scale bars: 500 nm (A, C, E, G), 200 nm (B, D, F, H), 50 nm (I), and 20 nm (J). White square box shows a filamentous array that is magnified in the inset (B, D, F, and H).