Mild head injury increasing the brain's vulnerability to a second concussive impact

• DOI: 10.3171/jns.2001.95.5.0859
• Publication Date: 2009-05-13T17:34:02Z
• Authors: Helmut L. Laurer; Florence M. Bareyre; Virginia M. Y. C....; John Q. Trojanowski; Luca Longhi; Rachel Hoover; Kathryn E. Saatman; Ramesh Raghupathi; Shigeru Hoshino; M. Sean Grady; Tracy K. McIntosh
• Keywords: Rotarod performance test

Object. Mild, traumatic repetitive head injury (RHI) leads to neurobehavioral impairment and is associated with the early onset of neurodegenerative disease. The authors developed an animal model investigate behavioral pathological changes RHI. Methods. Adult male C57BL/6 mice were subjected a single (43 mice), (two injuries 24 hours apart; 49 or no impact (36 mice). Cognitive function was assessed using Morris water maze test, neurological motor evaluated battery neuroscore, rotarod, rotating pole tests. animals also for cardiovascular changes, blood—brain barrier (BBB) breakdown, axonal injury, histopathological between 1 day 56 days after brain trauma. No cognitive dysfunction detected in any group. single-impact group showed mild according neuroscore test at only 3 postinjury, whereas RHI caused pronounced deficits 7 following second injury. Moreover, led functional during rotarod tests that not observed impact. Small areas cortical BBB breakdown profoundly exacerbated Immunohistochemical staining microtubule-associated protein—2 revealed marked regional loss immunoreactivity deposits β-amyloid tau brain-injured animal. Conclusions. On basis their results, suggest has increased vulnerability insult least initial episode