Long-Term Anesthetic-Dependent Hypoactivity after Repetitive Mild Traumatic Brain Injuries in Adolescent Mice
Autor: | Yiran Chen, Duan Xu, Donna M. Ferriero, Linda J. Noble-Haeusslein, Bridgette D. Semple, Jaclyn Carlson, Raha Sadjadi |
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Rok vydání: | 2016 |
Předmět: |
0301 basic medicine
Male Aging Neuroprotection White matter 03 medical and health sciences 0302 clinical medicine Developmental Neuroscience Concussion Brain Injuries Traumatic medicine Animals Maze Learning Pathological Brain Concussion Anesthetics Behavior Animal Brain medicine.disease Mice Inbred C57BL 030104 developmental biology medicine.anatomical_structure Neurology Isoflurane Anesthesia Anesthetic Anxiety medicine.symptom Hypoactivity Psychology 030217 neurology & neurosurgery medicine.drug |
Zdroj: | Developmental neuroscience. 38(3) |
ISSN: | 1421-9859 |
Popis: | Recent evidence supports the hypothesis that repetitive mild traumatic brain injuries (rmTBIs) culminate in neurological impairments and chronic neurodegeneration, which have wide-ranging implications for patient management and return-to-play decisions for athletes. Adolescents show a high prevalence of sports-related head injuries and may be particularly vulnerable to rmTBIs due to ongoing brain maturation. However, it remains unclear whether rmTBIs, below the threshold for acute neuronal injury or symptomology, influence long-term outcomes. To address this issue, we first defined a very mild injury in adolescent mice (postnatal day 35) as evidenced by an increase in Iba-1- labeled microglia in white matter in the acutely injured brain, in the absence of indices of cell death, axonal injury, and vasogenic edema. Using this level of injury severity and Avertin (2,2,2-tribromoethanol) as the anesthetic, we compared mice subjected to either a single mTBI or 2 rmTBIs, each separated by 48 h. Neurobehavioral assessments were conducted at 1 week and at 1 and 3 months postimpact. Mice subjected to rmTBIs showed transient anxiety and persistent and pronounced hypoactivity compared to sham control mice, alongside normal sensorimotor, cognitive, social, and emotional function. As isoflurane is more commonly used than Avertin in animal models of TBI, we next examined long-term outcomes after rmTBIs in mice that were anesthetized with this agent. However, there was no evidence of abnormal behaviors even with the addition of a third rmTBI. To determine whether isoflurane may be neuroprotective, we compared the acute pathology after a single mTBI in mice anesthetized with either Avertin or isoflurane. Pathological findings were more pronounced in the group exposed to Avertin compared to the isoflurane group. These collective findings reveal distinct behavioral phenotypes (transient anxiety and prolonged hypoactivity) that emerge in response to rmTBIs. Our findings further suggest that selected anesthetics may confer early neuroprotection after rmTBIs, and as such mask long-term abnormal phenotypes that may otherwise emerge as a consequence of acute pathogenesis. |
Databáze: | OpenAIRE |
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