CREB1 and viral infectious disease: To further ascertain this finding, we infused LV-VP16-CREB-GFP into the bilateral DG of mice by microinjection and delivered 15 Gy X ray to the hippocampus beginning from d 8 after virus infection and injected BrdU (200 mg/kg, i.p.)to label newly born cells in the hippocampus at 2 h after last irradiation.