HBSS-injected sciatic nerves are characterized by uniform, well-preserved myelin around the axons; infiltrating cells are absent (A). Mice injected with TMEV (B, C) show demyelination of the axons (demyelination presents as paler circles versus the dark well-myelinated axons; thick white arrow). In addition, the sciatic nerve contains cells which, due to their foamy appearance, appear to be macrophages (thin, white arrow) as well as myelin debris (thin black arrow). Sciatic nerves were osmicated, embedded in plastic and 1 micron sections prepared. Slides were stained with 4% para-phenylenediamene (PPD) and examined by light microscopy. Original magnification X1200.