An electron microscopic study of experimentally-induced HEV encephalitis.

A gnobiotic piglet, was inoculated intracerebrally with hemagglutinating encephalomyelitis virus (strain VW572). Mononuclear cells formed vascular cuffs and were disseminated in the brain parenchyma. A few neurons were surrounded by the same kind of cells. Virus particles morphologically similar to coronavirus particles were found in the cytoplasm of both chromatolytic light neurons and hyperchromic dark neurons. The particles were in vesicles of distended endoplasmic reticulum and in the hypertrophied Golgi apparatus.