Figure 4.

Co-immunostaining of active Casp6 with PHF-1. Micrographs show colocalization of active Casp6 (brown) and PHF-1 (red) in (A) neurofibrillary tangles (black arrow), (B) neuropil threads (black arrowhead) and a structure resembling a tangle stained only with anti-active Casp6 (white arrow). Left panel is a lower magnification indicating the area where the picture was taken (black arrow). Scale bar = 1 mm. Right panel is a higher magnification. Scale bar = 50 µm. (C) Micrograph showing punctate cytoplasmic anti-active Casp6 immunoreactivity in the APP Arctic case. The right panel represents a magnified image of the anti-active Casp6 immunopositive neurons with more or less PHF-1 immunoreactivity.