The Effect of Repeated Mild Traumatic Brain Injury on Ventricular Volume and Microglial Activation

As the leading cause of death and disability in individuals under the age of 45-years-old, Traumatic Brain Injury (TBI) is a public health crisis that demands the attention of the scientific and medical community [28]. The majority of all TBIs that occur in the United States each year are a non-deadly yet detrimental form of closed brain injury known as mild TBI (mTBI) or concussion [6]. Athletes, young people and military personnel all face a high risk of acquiring mTBI as a result of their environments. In our study we have chosen to model repeated mTBI (rmTBI) in the mouse in order to gain a boarder understanding of the mechanisms of injury and cellular changes occurring immediately after and months following rmTBI. Over a 3-month time course, we observed a gradual, yet significant, increase in lateral ventricular volume in mice that had induced rmTBI over that of control mice. In addition we observed changes in microglial morphology and activation throughout the brain immediately after rmTBI and up through 3-months following injury. Both of our findings contribute to the hypothesis that sustaining repeated rmTBIs over time can lead to an increased risk for neurodegeneration or poor recovery