Mild traumatic brain injury (mTBI), also known as concussion, is extremely commonplace and can occur to anyone, including children, athletes, military service members, and civilian adults. This supposedly temporary and insignificant injury is not presumed to have long-lasting effects. However, we have found that there may be long term consequences to mTBI; specifically, increased risk for Alzheimer’s Disease (AD). While mTBI does not result in direct brain tissue damage, it enlarges the perivascular space of the impact area, indicating vascular dysfunction that leads to blood brain barrier (BBB) breakdown. This results in impaired amyloid beta (Aβ) clearance and Aβ pathology, a hallmark of AD development. We are currently using a TBI (traumatic brain injury) mouse model to study what happens in the brain after impact, short-term and long-term.