Background: Traumatic Brain Injuries (TBIs) are a health crisis with over a million people suffering injuries each year in the United States. The majority of TBIs are mild injuries which often produce no period of unconsciousness and no gross damage to the brain or skull. A range of TBI animal models exist but many produce injuries too severe to characterize as mild. One TBI induction method commonly used is Controlled Cortical Impact (CCI) devices.

New Method: The purpose of this study is to assess a novel adaptation to CCI devices that allows for the induction of mild injuries that mimic human mild TBI (mTBI). In this apparatus, the mouse is placed on an elevated platform which utilizes a sensor to collapse the platform as the impactor hits the head.

Results: On the first day of injury, the repetitive dropping platform group had a significantly lower Time to Righting (TTR) than both control and single hit stationary platform groups. Additionally, on the first day of injury the single-hit stationary group had a significantly increased Time to Ambulation (TTA) compared to all other groups. Furthermore, this adaptation produces significantly less GFAP than CCI injuries performed without the falling platform.

Comparison with existing models: This model incorporates the high control of the CCI device that may be lost in weight-drop models of mild injury while also producing translational mild injuries.

Conclusion: This adaptation can be used in any CCI research lab to translationally study mild injuries. This will facilitate murine research into mTBI.