Radiation exposure prior to traumatic brain injury induces responses that differ as a function of animal age
Radiation exposure prior to traumatic brain injury induces responses that differ as a function of animal age
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DOI：
10.3109/09553002.2014.859761
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发表时间：
2014-03-01
影响因子：
2.6
通讯作者：
Fike, John R.
中科院分区：
文献类型：
--
作者：
Allen, Antino R.;Eilertson, Kirsten;Fike, John R.
目的：由于放射性恐怖主义、工业事故或军事情况造成的不受控制的辐射照射对平民人口构成持续的威胁。年龄在对辐射的敏感性方面起着重要作用;与成年人相比，年幼的儿童发生认知能力退化的风险更高。我们的目的是确定是否暴露于辐射影响的脆弱性的青少年海马随后中度traumatic injury.Materials and Methods：3周龄（少年）和8周龄的年轻成年C57 BL/J6雄性小鼠接受全身铯-137（Cs-137）照射与4灰色（戈伊）。一个月后，使用受控的皮质撞击系统诱导单侧创伤性脑损伤。照射后两个月，在Morris水迷宫中测试动物的视皮层依赖性认知表现。认知测试后，动物被安乐死，他们的大脑冷冻的免疫组化评估激活的小胶质细胞和海马齿状回的神经发生。结果：所有的动物都能够学习水迷宫任务，但是，治疗效果时，看到空间记忆保持进行了评估。在幼年时接受辐射，一个月后中度创伤性脑损伤的动物没有表现出空间记忆保留，即，都有认知障碍与此相反，所有组的动物被视为成年人表现出空间记忆保留的探针trials.Conclusion：虽然涉及的机制还不清楚，我们的研究结果表明，辐射增强了年轻的动物的脆弱性，发展认知损伤后，随后的创伤性损伤。
Purpose: Uncontrolled radiation exposure due to radiological terrorism, industrial accidents or military circumstances is a continuing threat for the civilian population. Age plays a major role in the susceptibility to radiation; younger children are at higher risk of developing cognitive deterioration when compared to adults. Our objective was to determine if an exposure to radiation affected the vulnerability of the juvenile hippocampus to a subsequent moderate traumatic injury.Materials and methods: Three-week-old (juvenile) and eight-week-old young adult C57BL/J6 male mice received whole body cesium-137 (Cs-137) irradiation with 4 gray (Gy). One month later, unilateral traumatic brain injury was induced using a controlled cortical impact system. Two months post-irradiation, animals were tested for hippocampus-dependent cognitive performance in the Morris water-maze. After cognitive testing, animals were euthanized and their brains frozen for immunohistochemical assessment of activated microglia and neurogenesis in the hippocampal dentate gyrus.Results: All animals were able to learn the water maze task; however, treatment effects were seen when spatial memory retention was assessed. Animals that received irradiation as juveniles followed by a moderate traumatic brain injury one month later did not show spatial memory retention, i.e., were cognitively impaired. In contrast, all groups of animals that were treated as adults showed spatial memory retention in the probe trials.Conclusion: Although the mechanisms involved are not clear, our results suggest that irradiation enhanced a young animal's vulnerability to develop cognitive injury following a subsequent traumatic injury.