EXPERIMENTAL MYELITIS CAUSED BY HERPES-SIMPLEX VIRUS TYPE-2 IN C57BL 6N AND BALB/CN MICE/

Intraperitoneal and intracranial inoculation of herpes simplex virus t ype 2 (HSV 2) into BALB/cN and C57BL/6N mice was carried out to induce experimental myelitis. The myelitis was clearly observed in C57BL/6N mice following intraperitoneal inoculation. Within 24 hours before dea th, the mice showed urinary and rectal incontinence and paraplegia of the hind legs. Randomly distributed, severe necrosis was demonstrated in the spinal cord, mainly at the lower cord. in BALB/cN mice the clin ical symptoms were not clearly observed, as the mice died shortly afte r their onset. Although Spinal cord necrosis was more prominent in C57 BL/6N mice than BALB/cN mice, brain necrosis was only found in the lat ter, and not in the former. Both strains of mouse showed marked nuclea r pyknosis of the nerve cells and slight nuclear pyknosis of the astro cytes in the brain where HSV 2 antigen was demonstrated immunohistoche mically. The antigen was also detected in the necrotic spinal cord. In contrast, intracranial inoculation of the virus into both strains did not cause myelitis. Spinal cord necrosis was not demonstrated and vir us DNA was not detected, by PCR, in spinal cord samples. In the brain, however, the virus was demonstrated by both PCR and immunohistochemis try.