Fig. 3

Notch1 intracellular and extracellular domains have distinct patterns in AD brains. a–a”) Fluorescent immunolabeling indicates that the Notch1 extracellular domain is abundantly expressed in the processes and is co-distributed with the Notch1 cytoplasmic fragment on the cell body of healthy neurons (a). In degenerating neurons (arrowhead in a’), the extracellular domain of Notch1 is strongly expressed in the soma and process, whereas the cytoplasmic portion of the receptor is condensed into the nucleus (arrowhead in a’). In addition, the two domains of Notch1 co-label some A β42 stained plaques (white arrows in a’ and insert in a") but not all (light blue arrows in a’). Notably, the Notch1 extracellular portion is strongly present in the amyloid fibrils, while the intracellular component is present at a lower level (a"). Scale bars in all panels are 40 μm