Figure 1

Photomicrographs of retinal cross-sections of unaffected (a, d) and naturally scrapie-affected (b, c, e) sheep. All layers of the control retina show normal organization and cytoarchitecture (a). Ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor segments (PS) and choroid (CHOR). Bar: 100 μm. In the scrapie-affected retina, not only was there a disorganization and thickening of the PS layer, but also an overall decrease of cellular density within the INL and ONL (b). Arrowhead indicates displaced photoreceptor nuclei in the PS layer. Bar: 100 μm. Immnohistochemical detection of abnormal PrP deposits (peroxydase-DAB, brown deposits-2G11 monoclonal mouse antibody) in a scrapie retina (c). Asterisks indicate the amorphous material accumulated in the photoreceptor outer segment layer. Bar: 100 μm. Müller cells labelling (GFAP rabbit polyclonal antibody peroxydase-DAB, brown coloration) in the retina from a control (d) and a naturally-scrapie affected sheep (e). Bars: 300 μm.