Repetitive Mild Traumatic Brain Injury in a Mouse Model

Repetitive mild traumatic brain injury has become a hot topic of academic and clinical research due to the neurological dysfunction in many retired pro athletes who have suffered such injuries. In this study, we evaluated a mouse model that simulates such injuries and analyzed cognitive and motor function post injury. The results were then correlated with histological findings. A weight drop model was used to induce repetitive mild head injuries in isoflurane anesthetized C57/BL6 male mice. Mice (n=7) were placed on a breakable foil platform over a sponge landing pad. A 43 gram steel weight was dropped through a guide tube from 28 inches onto the dorsal surface midline of the closed skull between the ears and eyes. Following the impact, the foil platform breaks allowing the mouse to experience rotational acceleration and land on the sponge pad. A single injury was performed daily M-F and again the following M-T (a total of 7 hits over 9 days). A group of sham injury mice (n=5) were anesthetized but did not receive TBI. Following injury, mice underwent behavioral testing for motor function, anxiety and cognitive to assess the effects of the repeated injury. Consistent with other studies of TBI in mice, animals with injury showed hyperactivity. Results showed that the mice with TBI showed significant (p The injury pattern in mice was designed to simulate the injury experience by repetitive concussion in athletes of all sports. The successful development of this model will allow future examination of pharmacological approaches to reduce mild repetitive head injury.