Quantifying injury tolerance for concussion is complicated by variability in the type and severity of post‐injury physiological and behavioral changes, as well as differences in the time course of these deficits. The current study outlined acute and chronic changes in behavioral metrics following rotational acceleration‐ induced concussion in rats. A unique injury model independently controlled magnitude and duration of the rotational acceleration pulse. Increasing rotational acceleration magnitude produced longer unconsciousness times, which were used as an assessment of acute injury severity. However, longer duration rotational accelerations produced changes in emotionality measured using the Elevated Plus Maze. Cognitive deficits were not apparent in the Morris Water Maze assessment, possibly due to the lower severity of rotational acceleration pulses incorporated in this study. Changes in emotionality evolved between acute and chronic assessments, in some cases increasing in severity and in others reversing polarity. These findings highlight the complexity of quantifying injury tolerance for concussion and demonstrate a need to incorporate rotational acceleration magnitude and duration in proposed metrics. Rotational velocity on its own was not a strong predictor of the magnitude or type of behavioral changes following concussion.
Keywords: traumatic brain injury, rotational acceleration, injury metrics, emotionality, behavioral assessment, rodent model