Tissue vulnerability is increased following repetitive mild traumatic brain injury in the rat
Autor: | Virginia Donovan, Andre Obenaus, Michael J. Muellner, Melissa S. Dulcich, Yufang Yin, Alena Mohd-Yusof, Joel E. Kamper, Udo Oyoyo, Richard E. Hartman, Lei Huang, Jacqueline S. Coats, Sarah Assaad |
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Rok vydání: | 2013 |
Předmět: |
Male
Pathology medicine.medical_specialty Traumatic brain injury Neuropathology Rats Sprague-Dawley Lesion Concussion medicine Animals Molecular Biology Brain Concussion medicine.diagnostic_test General Neuroscience Brain Histology Magnetic resonance imaging Recovery of Function medicine.disease Magnetic Resonance Imaging Rats Disease Models Animal Gliosis Brain Injuries Neurology (clinical) medicine.symptom Psychology Ex vivo Developmental Biology |
Zdroj: | Brain Research. 1499:109-120 |
ISSN: | 0006-8993 |
Popis: | Repetitive mild traumatic brain injury (rmTBI) is an important medical concern for active sports and military personnel. Multiple mild injuries may exacerbate tissue damage resulting in cumulative brain injury and poor functional recovery. In the present study, we investigated the time course of brain vulnerability to rmTBI in a rat model of mild cortical controlled impact. An initial mild injury was followed by a second injury unilaterally at an interval of 1, 3, or 7 days. RmTBI animals were compared to single mTBI and sham treated animals. Neuropathology was assessed using multi-modal magnetic resonance imaging (MRI), followed by ex vivo tissue immunohistochemistry. Neurological and behavioral outcomes were evaluated in a subset of animals receiving rmTBI 3 days apart and shams. RmTBI 1 or 3 days apart but not 7 days apart revealed significantly exacerbated MRI-definable lesion volumes compared to single mTBI and shams. Increases in cortical tissue damage, extravascular iron and glial activation assessed by histology/immunohistochemistry correlated with in vivo MRI findings where shorter intervals (1 or 3 days apart) resulted in greater tissue pathology. There were no neurological deficits associated with rmTBI 3 day animals. At 1 mo post-injury, animals with rmTBI 3 days apart showed reduced exploratory behaviors and subtle spatial learning memory impairments were observed. Collectively, our findings suggest that the mildly-impacted brain is more vulnerable to repetitive injury when delivered within 3 days following initial mTBI. |
Databáze: | OpenAIRE |
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