Neurophysiologist University of Minnesota Minneapolis, Minnesota
Abstract Text: Mild traumatic brain injuries (mTBI) are a major health problem in the United States, accounting for 90% of all reported TBIs. Most people who suffer a mTBI recover completely within a few weeks, however a subset of individuals may suffer long-term behavioral consequences months to years after the injury. There is no clear understanding of the factors that contribute to persistent symptoms following mTBI. Previous studies indicate that repeated mTBIs (rmTBI) increase the risk of future injuries and may worsen the outcome, which may explain the longterm consequences associated with mTBIs. Mental health problems such as anxiety, depression, and fear-avoidance have been reported as long-term consequences of mTBI among soldiers, athletes, and civilians. These disorders are all associated with persistent avoidance, which greatly reduces their productivity and negatively impacts their quality of life. To date, there have been few reports on the impact of TBI on the network neurophysiology underlying these maladaptive behavioral changes. Hence, it is critical to determine the underlying mechanism of how TBI alters avoidance behavior after TBI. The central hypothesis is that rmTBI induced persistent avoidance is related to changes in the synchrony of the mPFC-BLA-HPC circuitry. To test the above hypothesis, we will first determine the rmTBI-induced alterations in avoidance behavior in rats using simultaneous multi-site recordings. In the current study, we propose using microdrive to simultaneously record neural activity in the adult rat mPFC-BLA-HPC circuit while performing platform-mediated avoidance (PMA) tasks to investigate avoidance behavior and determine oscillatory synchrony in the circuit. We plan to investigate the neuronal synchrony in the mPFC-BLA-HPC during the PMA task following repetitive mTBI. In addition to advancing our understanding of how these disorders interact, neuronal network disruption could also lead to targeted treatments for this common co-morbidity among TBI survivors.
