Retinal damage in scrapie mice.

Retinal damages in mice infected with scrapie are reported. The effects ranged from no histopathological changes, through partial loss of the outer nuclear layer (ONL) to the most severe changes with complete loss of ONL cells and photoreceptors. For the most part, cells of inner nuclear and ganglion layers were spared. These changes were found in 23% of C57BL/6J mice injected with the ME7 strain of scrapie and in 28.5% of VM mice injected with the 87 V strain, while no changes were found in 13 IM mice injected with the 87 V strain of scrapie. The possible relation of these changes to scrapie infection and to light induced retinopathy is discussed.