Detection of HSV-I nucleic acids in rat vestibular ganglia

Rats were infected with HSV-I through the middle ear. DNA and RNA were extracted from the vestibular ganglia, trigeminal ganglia, cerebrum, cerebellum and brainstem in the productive or latent state after inoculation. DNA and RNA were applied for polymerase chain reaction (PCR) to detect HSV-I genomes. In particular, in the RNA PCR, the latent-associated transcript (LAT) mRNA, which is said to be present in the cervical or trigeminal ganglia at much lower levels during the productive state, was detected. In the productive state, DNA was clearly detected in all samples whereas LAT was detected only in the trigeminal ganglion on the inoculated side, cerebrum and cerebellum. In the latent state, DNA was detected in the vestibular ganglion only on the inoculated side, bilateral trigeminal ganglia, cerebrum, cerebellum and brainstem; LAT was detected in the vestibular ganglion on the inoculated side, the bilateral trigeminal ganglia and brainstem. These data indicate that HSV-I can establish latent infection in the vestibular ganglia in a similar way as in the cervical or trigeminai ganglia.