title: Cognitive performance of male and female C57BL/6J mice after repetitive concussive brain injuries.
abstract: In contact sports, repetitive concussive brain injury (rCBI) is the prevalent form of head injury seen in athletes. The need for effective treatment is urgent as rCBI has been associated with a host of cognitive, behavioral and neurological complaints. There has been a growing trend in the use of female animals in pre-clinical research, but few studies have investigated possible sex differences following rCBI. The goal of the current study was to determine any differences between male and female C57BL/6J mice on assessments of learning and memory after repetitive concussive injury. Following rCBI by impact to the scalp, male mice exhibited longer righting reflexes during acute recovery. In both sexes, there were no evident histopathological changes observed in the underlying cerebral cortex or hippocampus. Reactive astrogliosis was elevated in the corpus callosum and optic tract, and astrogliosis was slightly less in the optic tract of female mice. rCBI mice exhibited impairment during the learning phase of the Morris water maze (MWM), but female mice, in comparison to male mice, were observed to have superior spatial memory during standard MWM probe trials. Female mice were overall more active, evidenced by greater distances traveled in the y-maze and greater swim speeds in the MWM. The results of this study demonstrate sex differences in cognitive performance following rCBI and support previous research suggesting the neuroprotective role of sex in brain injury.
authors.affiliation: Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Velosky
authors.affiliation: Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Bethesda, MD, United States.
authors.forename: Laura B
authors.initials: LB
authors.lastname: Tucker
authors.affiliation: Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Bethesda, MD, United States.
authors.forename: Amanda H
authors.initials: AH
authors.lastname: Fu
authors.affiliation: Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States.
authors.forename: Jiong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Bethesda, MD, United States. Electronic address: Joseph.McCabe@usuhs.edu.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: McCabe
mesh_terms: D000818:Animals; D001924:Brain Concussion / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000473:pathology; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D003337:Corpus Callosum / Q000473:pathology; D005260:Female; D005911:Gliosis / Q000473:pathology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008810:Mice, Inbred C57BL; D009043:Motor Activity; D012727:Sex Characteristics; D065852:Spatial Memory / Q000502:physiology
keywords: Behavior; Cognition; Learning and memory; Sex differences; Traumatic brain injury