Virions and virus-associated structures within dendrites in an experimental flavovirus encephalomyelitis

In experimental yellow fever virus encephalomyelitis of adult albino mice, virions, and virus-associated structures were observed not only inside neuronal perikarya but also within dendrites of varied size. The finding permits the following explanations: (1) either the viral agent is synthesized in the nerve cell bodies and transported intradendritically in a proximodistal direction; or (2) virus morphogenesis takes place in neuronal perikarya and dendrites as well; or (3) both possiblities are equally valid. Some incidental findings were suggestive of virus release at postsynaptic dendrite membranes. They are discussed with reference to a hypothetical long-distance pathway of viral dissemination involving endocytosis of the agent by presynaptic axon terminals, intraaxonal virus decoating, and retrograde axoplasmic transport of the infectious nucleic acid to the cell soma.