Apoptosis induced in the spinal cord and dorsal root ganglion by infection of herpes simplex virus type 2 in the mouse.

After inoculation of a highly neuro-invasive strain of herpes simplex virus (HSV) type 2 (186) into the mouse hind-paw planter skin, many virus-positive neurons and glial cells were detected in the dorsal root ganglia (DRGs) and lumbar spinal cord by immunohistochemistry for HSV-2 antigen. A number of apoptotic cells were also observed in the spinal cord and DRGs by the terminal dUTP nick-end-labeling (TUNEL) method. Double labeling with the immunohistochemistry for HSV-2 and the TUNEL method revealed further that some glial and neuronal cells in the spinal cord, either infected or non-infected by HSV-2, showed apoptotic signs. In DRGs, however, apoptosis was detected in no neuronal cells, although some of HSV-2 -infected glial cells were apoptotic.