F2 and ischemia: But prothrombin may also enter the brain from the blood when the blood-brain barrier is disrupted.42 Indeed, in rodent models, areas of the brain with severe vascular damage resulting from ischemia were shown to have increased thrombin compared to regions that were relatively spared.43 with most (65%) thrombin co-localized in neurons, compared with microvessels (15%), and glial cells (10%).