Immediate in vivo response of the cortex and the blood-brain barrier following dynamic cortical deformation in the rat.

Although it is known that the brain can be injured by mechanical forces initiated at the moment of impact during trauma, it is not clear how the physical response of the brain dictates the injury patterns that occur in experimental models of traumatic brain injury. In this study, we investigated the mechanical response of the brain to a technique that creates a focal injury in the rat brain. Using a transient vacuum pulse applied to the exposed cortical surface, we found that the displacement of the cortex and the extent of in vivo blood-brain barrier breakdown were related significantly to the vacuum pressure level. The relationship between the response of the cortex and injury pattern points towards a new opportunity for control of the distribution and extent of injury patterns in animal models through a precise understanding of the model biomechanics, as well as potential improvements in means of preventing traumatic brain injury.