Fig. 4

Double immunofluorescent characterization of presenilin-associated protein (PSAP) and phosphorylated tau (pTau) (AT8 antibody) in pAD/AD human brain sections. (A) The low power view of immunofluorescently stained temporal lobe paraffin section with DAPI counterstain (from an AD case), with framed areas enlarged as other panel sets (B-E). Fluorescent markers are as indicated. PSAP and pTau immunofluorescence are partially colocalized in neuronal somata and dystrophic neurites (open arrows). Thus, neuronal somata singly labeled for PSAP (pointed by arrows), singly labeled for pTau (pointed by empty arrows), and double-labeled (pointed by arrowheads), are present in the same microscopic field. A diminished DAPI labeling is seen among many PSAP labeled neurons. (F) The numbers of the single- and double-labeled neurons based on quantification in the parahippocampal neocortex from four brains, with cell type ratios indicated (mean ± SD, n = 4, one-way ANOVA together with Bonferroni post hoc test). CA1-CA3: Ammon’s horn subregions; DG: dentate gyrus; Ent: entorhinal cortex; PHG: parahippocampal gyrus; Pro-S: prosubiculum; Pre-S: presubiculum; Sub: Subiculum; WM: white matter. Antibodies and fluorescence channels, and scale bars, are as indicated in the image panels.