fig3

Figure 3. Immunofluorescence detection and co-localization of retinal amyloid-beta oligomers and amyloid-beta plaques in dogs of the 6-10-year-old group. Retinal co-staining with anti-Aβ₄₀ (PRIOAD 12) and anti-Aβ₄₂ (PRIOAD 13) camelid-derived single domain antibody (green) and 4G8 antibody (red) of a 9-year-old Cocker spaniel dog (A-L). (A) A large number of Aβ₄₀ and (B) Aβ₄₂ oligomers were found in the GCL, INL, and ONL (white arrows, 40×). (C) Detection of Aβ₄₂ oligomers in the vasculature. 4G8 positive Aβ plaque-like deposits were observed in the (D and E) GCL, IPL, INL, and OPL of the retina (white arrows, 40×). Widespread co-localization was observed in the (G and H) retinal layers (white arrows, 40×). Co-localization of 4G8 positive Aβ plaque with (J) Aβ₄₀ and (K) Aβ₄₂ depositions (white arrowhead) showed with higher magnification (100×) in the GCL and INL of the same 9-year-old Cocker spaniel dog retinal section. (C) Aβ oligomers and (F) 4G8 positive Aβ plaques were observed in the retinal vasculature (white arrows). (I and L) Co-localization of Aβ oligomers and 4G8 positive Aβ plaques were exhibited with 40× and with higher 100× magnification in the retinal vessel wall, respectively (white arrowhead). The photomicrograph was derived from the peripheral region of the retina - away from the optic disc. Representative of 10 dogs examined from middle age group (6-10 years). GCL: Ganglion cell layer; IPL: inner plexiform layer; INL: inner nuclear layer; OPL: outer plexiform layer; ONL: outer nuclear layer.