Fig. 9

PrPSc accumulation at tips of rod bipolar cell dendrites and disappearance of dendrites. Epifluorescent microscopy analysis. a In uninfected retina, PrP (magenta) (blue arrowhead) and PKCα-positive rod bipolar cells (green) are seen near each other in the OPL. Many boutons (blue arrow) are present at dendritic tips of rod bipolar cells. b At 82 dpi, OPL appears similar to uninfected. Asterisk marks a rod bipolar cell body in INL. c At 104 dpi, PrP staining appears at dendritic tips. d At 118 dpi, most PKCα-positive dendrites display PrP at tips of processes (boutons) (arrow). e By 131 dpi most dendrites and dendritic boutons have disappeared, bipolar cell bodies remain (arrow), and PrPSc is distributed in large aggregates. Confocal analysis. f Maximum intensity projection shows PKCα and PrP staining of uninfected retina. Arrows indicate PKCα-positive rod bipolar cells with obvious boutons at the ends of dendrites. g A 118 dpi retina shows PrPSc arranged in bead-like deposits on dendrites, often replacing boutons. Magnification of boxes on left and right are shown below in panels h–k. h Confocal image shows association of PrPSc with dendrites and dendritic tips in area of right box from g. i–k Confocal images show merged, PrP and PKC staining of left box area in g. l In a high magnification of confocal image, anti-CtBP2 antibody marks ribbons (arrows) and confirms PrPSc deposits (magenta) on tips of dendrites (green) invaginating, but not touching, ribbons. Scale bars: a–e = 5 µm; f, g = 3 µm; h–k = 2 µm; l = 0.5 µm