English: Photo taken with a light microscope showing spongiform degeneration in the cerebral cortex of a patient who had died of Creutzfeldt-Jakob disease (CJD). The tissue section was embedded in paraffin-wax, sectioned at a thickness of approximately 5-10 microns, and stained with hematoxylin and eosin (H&E). Several large, pyramid-shaped neurons can be seen, along with the nuclei of glial cells. The scale bar in the lower right-hand corner represents a distance of 30 microns (0.03 millimeters).