Herpes simplex virus was inoculated through the round window membrane into the perilymphatic spaces of the guinea pig labyrinth. Immunofluorescent studies revealed that the viral antigens appeared in various areas of the labyrinth. The viral antigens were seen in the perilymphatic, endolymphatic, sensory and ganglion structures of the injected side. Histopathological changes were correspondent with localization of the viral antigens, and characteristic morphological changes of the tectorial membrane were seen in some of the animals. Although there were slight or no pathological changes on the opposite side, the viral antigens were also detected with less fluorescent intensity in the endolymphatic, sensory and ganglion structures.
Histopathological changes at the late stage of the viral infection were comfirmed after long-term observations. The neutralizing antibody titer after intralabyrinthine inoculation was studied compared with that after intraperitoneal inoculation.
