Tau accumulation in the Acb in TPD. A through G are immunohistochemistry with phosphorylation or conformational change specific tau antibodies. A, B, C and I: 4% paraformaldehyde-fixed, frozen-cut, 30 μm thick Sections. D through H are formalin-fixed, 10 μm thick, paraffin Sections. A: immunohistochemistry with AP422. Tau positive neurons are associated with many neuropil threads. Scale bars = 200 μm. B: immunohistochemistry with PHF-1. The majority of tau positive neurons show pretangle-like, diffuse or granular cytoplasmic labeling. Among them, apparent NFT are also seen but less frequently (arrow). Scale bar = 100 μm. C: immunohistochemistry with MC1, a conformational change specific antibody. Scale bar = 100 μm. D through G are immunohistochemistry with AT8. D: the vast majority of tau positive neurons are of medium-size but, occasionally, large neurons are also stained positively for tau (arrow). At the same magnification as C. E: tau positive neurons are not evenly distributed in the Acb. Scale bar = 500 μm. F: a glial coiled body. Scale bar = 25 μm. G and H: the nearby sections from the same case with AT8 immunohistochemistry (G) and Gallyas-Braak staining (H). I: thioflavin S staining reveals granular cytoplasmic labeling of neurons. Scale bar = 100 μm.