Fig 9. Ultrastructural and immunogold analyses of the neuronal alterations in the hippocampal dentate gyrus in the higher expresser mutant 3R Tau tg mice.

Vibratome sections were post-fixed with glutaraldehyde and embedded in epon-araldyte, and ultra-thin sections from the hippocampus were prepared for transmitted electron microscopy (TEM) and immunogold analysis. A. Representative electron micrographs from the neuropil of non-tg mice displaying normal characteristics for dentate granular (DG) cells, mitochondria, axons, synapses and dendrites. B. In the neuropil of the higher mutant 3R Tau tg Line 13 the mitochondria were enlarged and irregular, there were extensive axonal dystrophy and accumulation of electrodense bodies in dendrites and synapses accompanied by filamentous aggregates. C. In the non-tg no immunogold labeling was observed. D. With an antibody against 3R Tau, the intra-neuronal filamentous aggregates were decorated by gold particles in the tg mice. Mice were aged 8–10 months. Bar for A and B = 1 μm, for C and D = 100 nm.