Assessment of the effects of acute and repeated exposure to blast overpressure in rodents: toward a greater understanding of blast and the potential ramifications for injury in humans exposed to blast.
Assessment of the effects of acute and repeated exposure to blast overpressure in rodents: toward a greater understanding of blast and the potential ramifications for injury in humans exposed to blast.
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DOI：
10.3389/fneur.2012.00032
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发表时间：
2012
影响因子：
3.4
通讯作者：
Stone JR
中科院分区：
文献类型：
--
作者：
Ahlers ST;Vasserman-Stokes E;Shaughness MC;Hall AA;Shear DA;Chavko M;McCarron RM;Stone JR
由于暴露于简易爆炸装置（IED）而导致的轻度创伤性脑损伤（mTBI）已经激发了开发使用暴露于爆炸超压（BOP）来反映这种情况的动物模型的需求。在开发重复暴露于BOP的模型的过程中，我们试图初步表征啮齿动物中急性BOP暴露的影响，特别关注产生临床mTBI症状的BOP暴露水平。我们首先在平衡木上测量BOP对粗大运动功能的影响。单独的未麻醉大鼠组暴露（在不同的方向）36.6，74.5，和116.7 kPa BOP暴露在一个气动驱动的激波管。结果表明，暴露于116.7 kPa的大鼠表现出短暂的改变或意识丧失，表现为短暂的翻正丧失和平衡木上的疲劳增加。116.7 kPa暴露是急性BOP暴露的明显病理学阈值，约30%的大鼠表现出硬膜下出血和皮质挫伤的证据。暴露于116.7 kPa BOP的所有动物均表现出明显的肺出血迹象。在大鼠暴露于74.5 kPa面对BOP波和大鼠暴露于116.7 kPa在横向（侧）方向观察到顺行性记忆缺陷。接下来，我们评估了麻醉大鼠重复暴露于侧面或正面36.6 kPa BOP，每天一次，持续12天。结果表明，反复暴露在正面，但不是侧面，方向BOP波产生了短暂的学习缺陷的Morris水迷宫任务所示的显着更长的潜伏期，以达到淹没的平台，在第二和第三块的四块会议。这些数据的影响进行了讨论，在军事人员暴露于简易爆炸装置的mTBI的表现。最后，我们认为，有多种类型的长期脑损伤爆炸暴露。
Mild traumatic brain injury (mTBI) resulting from exposure to improvised explosive devices (IEDs) has fueled a requirement to develop animals models that mirror this condition using exposure to blast overpressure (BOP). En route to developing a model of repeated exposure to BOP we sought to initially characterize the effects of acute BOP exposure in rodents, focusing specifically on the levels of BOP exposure that produced clinical mTBI symptoms. We first measured BOP effects on gross motor function on a balance beam. Separate groups of unanesthetized rats were exposed (in different orientations) to 36.6, 74.5, and 116.7 kPa BOP exposure inside a pneumatically driven shock tube. Results demonstrated that rats exposed to 116.7 kPa demonstrated transient alterations or loss of consciousness indicated by a transient loss of righting and by increased latencies on the balance beam. The 116.7 kPa exposure was the threshold for overt pathology for acute BOP exposure with approximately 30% of rats presenting with evidence of subdural hemorrhage and cortical contusions. All animals exposed to 116.7 kPa BOP manifested evidence of significant pulmonary hemorrhage. Anterograde memory deficits were observed in rats exposed to 74.5 kPa facing the BOP wave and rats exposed to 116.7 kPa in the lateral (side) orientation. We next assessed repeated exposure to either lateral or frontal 36.6 kPa BOP in anesthetized rats, once per day for 12 days. Results showed that repeated exposure in the frontal, but not side, orientation to the BOP wave produced a transitory learning deficit on a Morris water maze task as shown by significantly longer latencies to reach the submerged platform in the second and third blocks of a four block session. Implications of these data are discussed in relation to the manifestation of mTBI in military personnel exposed to IEDs. Finally, we suggest that there are multiple types of long-term brain injury from blast exposure.