Talk abstracts

Talk on Tuesday 09:30-09:45am submitted by Michaela Breach

Mild pediatric traumatic brain injury in rats produces sex-specific effects on gliosis, mast cells, and social behavior

Michaela R Breach (Neuroscience Graduate Program), Brooke J. Schatz, Habib E. Akouri (Department of Psychology), Ale Zaleta-Lastra, Zoe M. Tapp (Neuroscience Graduate Program), Ashley E. Walters (Department of Psychology), Cole Vonder Haar, Olga N. Kokiko-Cochran (Department of Neuroscience, Chronic Brain Injury Program, Institute for Behavioral Medicine Research), Kathryn M. Lenz (Department of Psychology, Department of Neuroscience, Chronic Brain Injury Program, Institute for Behavioral Medicine Research)

Abstract:
Traumatic brain injury (TBI) in the pediatric period increases the risk for long-term physical, cognitive, and psychosocial impairment. There are also sex differences in long-term outcomes following pediatric TBI. However, the mechanisms through which pediatric TBI impacts brain and behavioral development are not well understood, and even less is known about the influence of sex. Methods: In this study, male and female Sprague Dawley rats received a lateral fluid percussion injury (1.2 atmospheres), sham surgery, or were undisturbed (naïve) on postnatal day 15. We assessed long-term behavioral outcomes and select neuroimmune and neuroanatomical endpoints that could be linked to behavioral alterations, including gliosis, brain mast cell number, oxytocin neurons and fibers, and perineuronal nets. Results: TBI increased mast cells relative to naïves at 3 days post-injury (DPI). By 7 DPI, TBI females had elevated mast cells relative to shams. Surgery increased microgliosis at 3 DPI and had sex-specific effects on astrogliosis. No effects were found on oxytocin or perineuronal nets. Regarding behavior, surgery increased rearing and had sex- and session-specific effects on play and allogrooming in juveniles. In adulthood, TBI reduced sociability relative to naïves in both sexes. Social avoidance was significantly increased in TBI females and reduced in TBI males. Conclusions: Pediatric TBI impairs adult social behavior in rats, and some acute neuroimmune and chronic behavioral outcomes may be more impacted in females. This research adds new insight into potential mechanisms underlying sex differences in pediatric TBI-induced impairment and provides a basis for future studies assessing novel therapeutic interventions.

Keywords: Traumatic Brain Injury, Sex Differences, Behavior