Microglia are not required for prion-induced retinal photoreceptor degeneration

Progressive retinal degeneration in tgGFP/RFP mice after intracerebral 79A scrapie inoculation. a H&E stain of retina from a mock-inoculated mouse at 162 dpi showing normal retinal structure. Yellow bar indicates thickness of outer nuclear layer (ONL), which contains nuclei of photoreceptor (PR) cells. b Retina from a 79A scrapie-infected mouse at 124 dpi showing thinning of ONL (yellow bar), alteration of the IS and OS regions and presence of an infiltrating mononuclear cell in the OS region (arrow). c Retina from a 79A scrapie-infected mouse at 153 dpi shows nearly complete degeneration of ONL (yellow bar) and loss of IS and OS regions. Thinning of inner nuclear layer (INL) and inner plexiform layer (IPL) is also apparent. GC？=？ganglion cell layer, IPL？=？inner plexiform layer, INL？=？inner nuclear layer, OPL？=？outer plexiform layer, ONL？=？outer nuclear layer with photoreceptor cell nuclei, IS？=？inner segment of photoreceptors, OS？=？outer segment of the photoreceptors, RPE？=？retinal pigment epithelium. Scale bar？=？100u