Fig. 1.

Visna-maedi virus-infected sheep. a Ewe 1: Grossly, the cerebrum has multifocal to coalescing, irregular, yellow to brown, soft, periventricular areas (arrow). b–f Histologic findings. b Periventricular areas of the brain with necrosis, severe inflammatory infiltrate, cholesterol clefts, and deposition of mineral (arrow). H&E, 600 μm. c Higher magnification of the periventricular areas with deposition of mineral material (arrow), cholesterol clefts, and mononuclear infiltrate. H&E, 100 μm. d Marked infiltrate of macrophages and a smaller number of lymphocytes. H&E, 100 μm. e Numerous strongly immunolabeled macrophages infiltrate the white matter. IHC anti-Iba1, 100 μm. f The choroid plexus is expanded by multifocal infiltration of lymphocytes in the form of follicles-like structures (arrow). H&E, 600 μm