A traumatic brain injury causes several disorders that are characterized by the delayed occurrence of changes in brain function, such as posttraumatic epilepsy. Because brain injuries are complicated, we have developed a simplified experimental approach that allows us to look at one particular consequence of brain injury in isolation, namely the loss of normal input after nerve pathways are severed during an injury. We have evidence that the brain cells that lose their normal inputs try to compensate for the lack of normal activity. Unfortunately, that this ‘sensible’ response of the cells results in an unintended consequence- epilepsy. Using laboratory rats, we will be testing the mechanisms that the cells use to compensate for the lack of activity and also test a class of medicines that may counteract those changes. We hope that our work will lead to novel treatments that can prevent the development of epilepsy after brain injury.