Traumatic brain injury is a risk factor for epilepsy, though the relationship is not understood. A new study in mice, published in Cerebral Cortex, identifies increased levels of a specific neurotransmitter as a contributing factor connecting traumatic brain injury (TBI) to post-traumatic epilepsy. The findings suggest that damage to brain cells called interneurons disrupts neurotransmitter levels and plays a role in the development of epilepsy after a traumatic brain injury.