Vet. Path. 11: [3-19 (1974) Ultrastructural Studies of Spleens, Brains, and Brain Cell Cultures of Mice with Scrapie

Abstract. Mouse brains, cell cultures of mouse brains, and spleens from mice with scrapie were examined by electron microscopy. Brains and spleens of 10 scrapie-inoculated and control mice were studied. Seven brain-cell cultures, four of which were from mice inoculated intracerebrally or subcutaneously with scrapie, were examined. Status spongiosus and vacuolated neurons were found in the brains. Structures 35 nm in diameter were seen in the brains of mice inoculated intracerebrally. They were not evident in cell cultures, although a vacuolated structure was found in one such culture. No significant changes were found in the spleens. Through electron microscopy, investigators have sought to show scrapie virus and its associated changes. The established histological diagnostic cri-teria- neuronal vacuolation, astrocytic hypertrophy and status spongiosus-have been studied also by this means. Natural cases of scrapie have neuronal vacuolation and intravacuolar budding of vesicles and cytoplasmic processes, with some vacuolated neurons containing membrane-bound accumulations of 35-nm particles [2]. There are other reports of similar findings without th