BILATERAL ELECTRORETINOGRAPHIC CHANGES INDUCED BY UNILATERAL INTRA-VISUAL CORTEX INOCULATION OF HERPES-SIMPLEX VIRUS TYPE-1 IN BALB C MICE/

Intra-visual cortex inoculation of 10(2) plaque-forming units of herpe s simplex virus type 1 (KOS-63) induced physiologic and morphologic re tinal changes in 62.3% (33/53) of infected animals; of these, 91% were bilateral. In contrast, inoculation of the same viral titers into the frontal lobe induced retinal alterations in only 13.3% (2/15). Initia lly, there was a decrease of the b-wave amplitude and retinal sensitiv ity and necrotic changes of the ganglion cells and nuclei in the inner nuclear layer. Immunoperoxidase staining for virus-specific antigens showed positive staining of the same cell type. Over time, there was a progressive decrease in the electroretinogram until it was extinguish ed and the retina was replaced by gliotic tissue. Parallel viral recov ery studies demonstrated detectable infectious virus in one of eight e yes on day 2 after inoculation and in three of eight eyes on day 4. Th ereafter, there was an increase in the percentage of eyes with infecti ous virus and a concomitant increase in viral titers. Immunoperoxidase staining of brain sections obtained on days 6 through 8 demonstrated virus-specific antigens on cells in the lateral geniculate nuclei and the suprachiasmatic nuclei bilaterally.