MILD TRAUMATIC BRAIN INJURY IMPAIRS SPATIAL WORKING MEMORY IN RATS

Mild Traumatic Brain Injury (mTBI), or concussion, is the most common form of traumatic brain injury, which accounts for about 80% of cases. It is a common problem in contact sports and may lead to cognitive impairment. This study used the Wayne State University closed-head weight-drop model in lightly anesthetized and unrestrained Long Evans rats. This model allows for the rapid acceleration and deceleration of the head and torso, similar to the biomechanics in human mTBI. Rats were administered a single weight drop. Sham animals were treated the same as the mTBI group but were not subjected to weight drop. Rats were trained in an 8-arm radial maze to assess spatial working memory before and after weight drop manipulation. We observed that the injured rats spatial working memory performance significantly declined compared to the sham rats (cohens d = 1.88). Specifically, the performance of the sham group continued to improve after the sham procedure, whereas the performance of the injury group decreased. This study suggests the WDM model produces a deficit in spatial working memory in rats.