Figure 1.
Neuropathological hallmarks of human AD can be recapitulated in ATP-deprived human and chick primary neurons. a, b, Hyperphosphorylation of tau at Ser262/356 (immunolabeled with the 12E8 antibody) and striated neurites are early markers of AD. Immunofluorescent staining of sections of frontal cortex from human AD brain show strong 12E8 reactivity in neurofibrillary tangles in individual neurons (a) and abundant linear arrays of 12E8-labeled inclusions in neurites (a, b, arrows). c, Human primary neuronal cell cultures labeled with the 12E8 antibody (red) and total tau antibody (green), after 30 min AM treatment (plus DAPI in blue in merged image). Tapered pMAP-positive rods were observed throughout the neurites (arrows). d, e, Primary chick neurons (7 div) treated with AM for 15 min also rapidly accumulate rod-like 12E8-positive inclusions (red) that frequently form linear striations within single neurites (e, arrowhead). Rods were not enriched with total tau (c, d, green), indicating that inclusions contain MAP/tau specifically phosphorylated within the microtubule-binding KXGS motifs, as immunostained with 12E8 (red). f, Control chick neurons show evenly distributed 12E8 staining along neurites with only the occasional rod-like accumulation (arrow). Scale bars: a, b, 10 μm; c–f, 20 μm.