Adult male C57BL/6J mice, aged 10-12 weeks and weighing 20 to 24 g. Briefly, following anesthesia with isoflurane (4% for induction and 12% for maintenance), mice were mounted on a stereotaxic frame. A midsagittal incision was performed in the scalp under sterile conditions and a 4.5 mm diameter circular craniotomy was made over the left parietotemporal cortex with a burr drill. Then, the skullcap was gently removed and a 3.0 mm diameter round and flat tip was carefully placed vertically to the dural surface. The electromagnetic controlled cortical impact device was set to 5.0 m/s for strike velocity, 2.0 mm for strike depth and 100 ms for dwell time. A sterile plastic film covered the bone window and intermittent sutures of the skin, and disinfection with iodophor were performed. The entire procedure required 15-30 min per mouse.