Blood–brain barrier disruption and ventricular enlargement are the earliest neuropathological changes in rats with repeated sub-concussive impacts over 2 weeks

Abstract Repeated sub-concussive impact (e.g . soccer ball heading), a significantly lighter form of mild traumatic brain injury, is increasingly suggested to cumulatively alter structure and compromise neurobehavioural function in the long-term. However, underlying mechanisms whereby repeated long-term sub-concussion induces cerebral structural changes are currently unknown. Here, we utilised an established rat model investigate effects on size lateral ventricles, cerebrovascular blood–brain barrier (BBB) integrity, neuroinflammation, oxidative stress, biochemical distribution. Following 3 days per week for 2 weeks, rats showed enlarged ventricles compared with receiving sham-only procedure. The also presented significant BBB dysfunction cortex hippocampal formation, whilst neuromotor assessed by beamwalk rotarod tests were comparable sham rats. Immunofluorescent spectroscopic microscopy analyses revealed no lipid distribution or protein aggregation, within hippocampus cortex. These data collectively indicate that weeks induce ventriculomegaly disruption, preceding deficits.