Mechanisms of microthrombi formation after experimental subarachnoid hemorrhage

► Mice have constricted brain arterioles 2 days after subarachnoid hemorrhage. ► Mice have microthrombi in brain arterioles 2 days after subarachnoid hemorrhage. ► Nitric oxide is reduced in mouse brain 2 days after subarachnoid hemorrhage. ► Membrane P-selectin is increased in mouse brain arterioles 2 days after subarachnoid hemorrhage. ► Reduced nitric oxide and increased P-selectin may contribute to microthrombus formation after subarachnoid hemorrhage.