OLIG2 and infection: Examining hippocampal sub region CA3, an area receiving myelination from septal GABAergic neurons[23,24] and known for synaptic stripping and inflammation during WNV-E218A infection, we observed a loss of both IL-33+ astrocytes (GFAP+) and IL-33+ oligodendrocyte-lineage cells (Olig2+) 7 days post-infection (Fig 2B and 2C).