An ultrastructure study of cerebellar lesions induced in mice by three inoculations of avirulent Semliki forest virus.

An ultrastructural study of cerebellar lesions involving axonal and myelin degeneration induced in adult Swiss A2G mice by 3 intraperitoneal inoculations of avirulent Semliki Forest virus is described. Cerebellar white matter samples examined by light and electron miscroscopy 21 days after the first virus infection revealed microcystic areas, degenerating axons, macrophages containing myelin debris as well as normal elements. By light microscopy foci of myelin loss were apparent. At 28 days groups of degenerating axons were apparent in the white matter. No virus was seen in any of the sections.