Abstract
DDD mice, 4 and 12 week-old, were infected with type I herpes simplex virus (HSV) by intranasal inoculation and the pathogenesis of HSV encephalitis was examined with the passage of time by immunofluorescence in reference to histopathological changes and virus isolation. Virus solutions (high and low dose) were dropped into the nasal cavity and mice were divided into 4 groups. Almost all 4 week-old mice died 6-7 days after virus inoculation with high dose. Viral antigens were demonstrated in the epithelia of nasal cavity, olfactory bulb, olfactory area of the cerebrum, and also in the trigeminal ganglia, pons and medulla oblongata widely. Olfactory epithelia had erosion with infiltration of inflammatory cells and hemorrha-ges. In the olfactory bulb and the trigeminal ganglia, degeneration of neurons, infiltration of small round cells, cell debris and hemorrhages were observed with occasional intranuclear inclusion bodies. In the pathogenesis of acute HSV encephalitis by intranasal infection, two infectious routes were suggested, olfactory and trigeminal nerve. The latter is intimated as invasive course of the HSV into the central nervous system.
