Figure 1.
Neuropathologic changes in Swiss mice after inoculation with RML scrapie prions. (a) Hematoxylin and eosin stain of a serial section of the hippocampus shows spongiform degeneration of the neuropil, with vacuoles 10–30 μm in diameter. Brain tissue was immersion fixed in 10% buffered formalin solution after the animals had been sacrificed and was then embedded in paraffin. Py, pyramidal cell layer; SR, stratum radiatum. (b) Glial fibrillary acidic protein (GFAP) immunohistochemistry of a serial section of the hippocampus shows numerous reactive astrocytes. (Bar in b = 50 μm and also applies to a.) Photomicrographs were prepared by Stephen J. DeArmond.