Fig. 5

Topographical distribution of neurofibrillary changes at the midbrain and pons. Representative virtual slide images double-immunofluorolabeled with anti-4R (green) and 3R (red) tau, with colocalization (yellow) on overlays, of the midbrain (a, b, case 18 and 10, respectively) and pons (c, case 18). At the midbrain, the neurofibrillary changes were accentuated at the ventral PAG (a, b, open arrow), LRN (a, open arrowhead), and substantia nigra (SN, a, solid arrowhead). The neurofibrillary changes often affected the ventral half of the PAG (a, b, open arrows) more severely than the dorsal half (a, b, solid arrows). By comparison to KB-stained section (d, case 10, nearby section to b), the lesions in the ventral PAG coincided with the area where the large neurons of DRN were present (d, open arrow). The oculomotor nuclei (b, d, III) were not involved with neurofibrillary changes. At the pons, the neurofibrillary changes were accentuated at the LC (c, open arrows), DRN (c, open arrowheads), and median raphe nucleus (MRN, c, solid arrowheads). Scale bar = 2 mm (a, c), and 500 μm (b, d)