Triple immunofluorescence of TOC1, pS422, and MN423. Immunofluorescence of TOC1 (green), pS422 (blue), and MN423 (red) in the nbM revealed a relatively higher proportion of TOC1+/pS422+ neurons (arrowhead) in NCI (A–D) and MCI (E–H) cases. In MCI, MN423 staining was observed more frequently and thus the number of TOC1+/pS422+/MN423+ neurons (arrow) increased. Triple-labeled NB neurons were also observed in AD (H–L; arrow), however, double-labeled TOC1+/pS422+ neurons persisted in AD (arrowhead). Scale bar: L = 100 μm, and applies to all images.