Researchers at the University of Colorado Anschutz Medical Campus have discovered how the most severe forms of West Nile virus cause memory loss and mood disorders, opening the door to potential new treatments for the mosquito-borne illness.
The study, published in the journal Nature, says 50 percent of patients who survive the most damaging kind of West Nile infection often go on to develop memory loss, learning difficulties, a lack of concentration and irritability.
Exactly why this happens has been a mystery until now.
Researchers discovered that the virus doesn’t kill off neurons but sparks inflammation that prunes synapses, the connections that carry messages between nerve cells.
“What we found in mice, and later confirmed in humans, is that it’s not the death of cells that causes memory loss, it’s the loss of nerve cell connections,” said study co-author Kenneth Tyler, MD, chairman of the department of neurology at the University of Colorado School of Medicine. “The viral infection activates microglial cells and complement pathways which are helping to fight the infection but in turn end up destroying synapses.”
Read more at CU Anschutz