Case of the vanishing virus

Viruses that leave no molecular fingerprints as they destroy brain cells may be behind certain psychiatric and neurological disorders, according to Yale investigators. In a test of their hypothesis they introduced a recombinant virus, vesicular stomatitis virus, into an adult mouse through its nose. The virus, which is not dangerous to humans, traveled down the olfactory nerve, into the periglomerular neurons, past the mitral cell layer, through granule cells and toward the brain’s subventrical zone. Then it vanished.

“In young mice, the virus may get past the olfactory system and then may selectively infect and damage other brain regions such as the locus coeruleus and dorsal raphe that are the targets for many psychiatric medicines,” said Anthony N. van den Pol, Ph.D., professor of neurosurgery and lead author of the study, published in February in the Journal of Virology. “The virus can be eliminated by the immune system and leave no trace in the brain, but nerve cells in very specific areas of the brain are lost. This is a potential model for viruses that may infect the brain at one stage of life, and then disappear, but potentially cause long-lasting psychiatric and neurological dysfunction.”