作者想感谢艾略特他的资产阶级用于技术援助。这项工作是由国家机构的健康补助R01HD059288和R01NS069629的。

1。横向闭合性损伤中的作用<ol><li>麻醉的小鼠腹腔注射氯胺酮和甲苯噻嗪的混合物。鼠标的头部，然后准备切口用碘擦洗。 </li><li>执行去骨瓣超过使用3毫米（外径）环锯的右顶叶面积。 </li><li>安全鲁尔-LOC针轮毂（内直径为3毫米）在骨瓣使用cyanoarylate和牙齿的丙烯酸。 </li><li> 24小时后，麻醉吸入异氟醚通过鼠标使用​​。 </li><li>一旦恢复正常的呼吸，但之前鼠标的刺激变得敏感，通过液压冲击伤设备，提供20毫秒的脉冲生理盐水入颅。 </li><li>伤后立即取下集线器，reanaesthetize鼠标采用异氟醚，和头皮缝合关闭。 假手术组将收到一个相同的程序与步骤1.5省略。 </li></ol> 2。行为分析 - 恐惧RESPONSE <ol><li>处理小鼠连续两天之前，条件性恐惧反应（CFR）培训。 </li><li>将鼠标放置在空调室管理1.5毫安地板冲击2秒的前3分钟。发布鼠标在一个额外的30秒内的腔室。 </li><li>的延迟时间（通常24小时）后，返回鼠标调节室持续5分钟。评估冻结5秒的时间间隔。 分析包括两个群体，在我们的例子脑损伤的小鼠和假手术组比较的相对量冻结的时间。冻结速率较低（与对照组比较）表示无法保留上下文之间的关联和地面的冲击，记忆障碍和认知功能障碍的迹象。 </li></ol> 3。急性海马脑片准备 *注:麻醉用钟罩只能实现终端程序（如本文所述的大脑解剖）。 <ol><li>后7天损伤，使1 L的人工脑脊髓液（人工脑脊液）和250毫升蔗糖裁剪解决方案。 </li><li>使用冰宽松，以确保所有脑片制备过程中使用的仪器和解决方案是冰冷的。 </li><li>使用异氟醚麻醉小鼠。快速，轻轻取出大脑中蔗糖从鼠标和地点。 </li><li>修剪大脑和一滴胶水前面的琼脂块切割面。 </li><li>切350微米厚的冠状切片，你应该能够得到完整的海马电路与4或5片。 </li><li>孵育切片至少1小时，在37°C。 </li></ol> 4。外场电位记录<ol><li>拉硼硅玻璃电极到2-5MΩs垂直拉拔器。 </li><li>将片室，并插入电极，电极支架上。 </li><li>成片，如perforant的路径或Schaffer侧支在轴突道的刺激电极降低。下记录电极入位置，同时监测输出的痕迹，以确保电极是在相同的z级（深度）。当达到最大反应，刺激电流电平保持恒定，电极是在相同的z级。 </li><li>得到的曲线由三个部分组成:突触前纤维的凌空抽射，领域外突触后电位（fEPSP的），和突触后的人口秒杀。一些准备工作的组成部分重叠时间，使分析更加困难。如果有模棱两可之间是否响应是突触前或突触后，APV和CNQX可以加入到熔池中以阻止兴奋传导，而所有剩余的信号将是突触前的原点。 </li><li>刺激方案各不相同，生产三个不同的实验类型:输入/输出曲线，双脉冲录音，并长期可塑性的实验。 分析通常由比较的fEPSP的斜率的测量，在两个大脑损伤的小鼠和假对面操作控制，控制输入强度通过测量光纤凌空。 </li></ol> 5。可视膜片钳记录<ol><li>准备片，电极，和钻机记录先前如上所述到步骤4.2。 </li><li>只考虑细胞深度超过80微米到接近表面的细胞组织，将是死的，和/或减少的连接。方法与在电极上的正压力，以确保它不会被堵塞，因为它向下移动穿过组织的细胞。当电极轻轻触及细胞施加负压，以便创建一个&#39;gigaseal&#39;之间的电极和质膜。 </li><li>应用短脉冲串的负压，以便破裂下的plama膜的电极，并实现整个小区的配置。 </li><li>消除使用放大器的电容瞬态和串联电阻补偿。补偿的单元格中的串联电阻是必不可少的，以确保ccurate测量。 </li><li>两种模式，可以进行单细胞录音:电流钳（测量电压）膜和电压钳位（测量电流通过膜中的离子通道）。 分析可能出现的类型很多，但在我们的例子中，主要包括生物物理分析，定量分析脑损伤的小鼠和假手术组的突触电流的速度和规模。 </li></ol> 6。电压敏感染料成像（VSD） <ol><li>准备记录片和钻机上述步骤4.2。 </li><li> 50μl乙醇混合1毫克二3 ANEPPDHQ的到，准备染料股票分配2微升等份箔纸包裹的管道，储存在-20°C每天工作染料溶液，稀释1:200脑脊液。 </li><li>孵育湿滤纸片上脑脊液和染色与90μl的染料16分钟;与脑脊液和接口在录音室冲洗。 </li><li>调节光stimulatio器Ň，直到反应强度集中在中间的摄像头的范围。画像通常500-1000帧每秒的速率获得。 </li><li>电刺激，让初期的快速光漂白稳定之前触发快门的光刺激200毫秒。替代的采集试验之间的电刺激，非电刺激，以允许购买减法非刺激的背景。录制休息的光强度（荧光值与快门关闭）之前打开快门。每个VSD的审判将是一个y像素x像素的荧光读数的时间"电影"。记录10 - 12的VSD试验在每个测试条件。 </li><li>所有的测量都是上执行帧内像素的预电刺激归一化的荧光变化，DF / F，它被计算为如下: 减去休息的光强度VSD的原料收购的试验。如果在每次试验中的每个像素，根据电刺激前的平均值，该正常化试验，减去团结。电刺激和非电刺激试验。创建从非电刺激试验的平均的"背景荧光"试验，并从电刺激试验试减去这个背景。进一步的分析，通常进行的平均值为10 - 12个这样的试验中，也通常在空间和时间，以改善信噪比过滤。 </li></ol> 7。生化分析的区域解剖<ol><li>如前面所述的从小鼠中取出的大脑。 </li><li>准备切片组织菜刀。 </li><li>莱节平，显微切割CA1区和DG。 </li><li>裂解缓冲液中含有蛋白酶抑制剂，立即浸入冷水中。冷冻在液氮中并存储在-80°C。 </li></ol> 8。代表性的成果我们的实验通常开始与行为数据，以确认预期版中存在的脑损伤小鼠的认知功能障碍。 ，因为它是海马依赖的行为，是可靠的，只需要一个训练阶段，以及一个测试环节，我们采用情境恐惧反应测试。在图2中所示的数据表示行为的测试，以测量顺行存储器，然而，也可以使用测试测量逆行性记忆受伤之前进行，如果训练会话。 兴奋性突触后电位（fEPSPs）测量，以确定的净突触效能的一个人口众多的细胞（ 图3A）。我们通常采用三种不同类型的刺激模式，每个得到其自己的结果和结论。首先，通过一系列的步骤，通过增加的刺激强度，我们创建了一个输入/输出曲线（ 图3B / C）。 接着，通过提供两个相同强度的单独的刺激D的一个短暂的延迟（通常为50毫秒），我们调查潜在的突触囊泡释放概率的改变。此外，我们经常执行长时程增强（LTP）实验。建立基线响应，简短的高频刺激（通常为100Hz的）后，在相同强度的传递，导致细胞内的级联，导致恢复正常时刺激一个增效突触反应。 从全细胞膜片夹紧细胞的电活动可以在两种模式下记录。在电压钳位模式，实验者控制膜片夹紧单元格中参照浴膜电压，通过相关联的计算机软件与放大器。在这种情况下，电流调解突触后的事件被记录，提供突触前释放频率有关下列内容的信息，数字突触后受体激活和水泡性神经递质的浓度（ 图4A）。在电流钳模式下，实验者操纵注入的电流和测量的电压响应。这可能是有用的，以确定的动作电位的特性，如动作电位的阈值和半角。这些特性允许兴奋或抑制基于他们的动作电位的放电模式（ 图4B）的神经元的功能分类。为了验证蜂窝的身份，我们建议记录后，目视确认身份的存在或不存在的树突棘与路西法黄色填充单元格。 （ 图4C，D）。 使用电压敏感染料测量膜电压的变化的实验结果的一个例子示出在图5中。在这种情况下，刺激电极已被放置在Schaffer侧支途径所得CA1区的神经元的电活动进行分析。电压敏感染料不报告膜电位的绝对值，而是吨他的电压变化，从基线条件无刺激。然而，比较两个条件（ 如脑受伤与假手术）的分析可用于确定不能使用fEPSPs或全细胞膜片钳记录测量的生理改变的时空参数。 <img alt="图1" src="/files/ftp_upload/4411/4411fig1.jpg" /> 图1。海马电路图。部分通过海马的水平。在海马的主要途径，通过显示为黄色。工程通过的perforant的途径进入齿状回齿状回颗粒细胞的树突形成突触内嗅皮质神经元的轴突从。颗粒细胞的轴突项目通过苔藓纤维通路CA3 CA3神经元的树突形成突触。 CA3神经元的项目通过Schaffer侧支途径到的dendrit上的轴突ES CA1锥体细胞。通过下脚的海马CA1锥体细胞的轴突投射出的。注:还描绘了CA3锥体细胞的轴突投射到对侧海马通过伞的抵押品。 （CA1 CA2:的考纽Ammonis 1，的考纽Ammonis 2，CA3:的考纽Ammonis 3，DG:齿状回，虚线表示的细胞体层，实线表示结构边界）。 <img alt="图2" src="/files/ftp_upload/4411/4411fig2.jpg" /> 图2。代表行为数据。A:行为数据，描绘脑损伤小鼠（FPI）和假手术对照组（假）的条件性恐惧反应模式之间的差异，冻结速率。培训发生在损伤后第 6天，24小时后测试期间发生。 （**表示P &lt;0.01）。 <img alt="图3" fo:content-wIDþ="5英寸的FO:src ="/ files/ftp_upload/4411/4411fig3highres.jpg"SRC ="/ files/ftp_upload/4411/4411fig3.jpg"/&gt; 图3。代表细胞外记录数据。A:的场兴奋性突触后电位（fEPSP的）记录CA1区的一个例子。第一向下偏转的刺激的神器，其次由突触前纤维凌空和最后fEPSP的。 B:输入/输出曲线描绘了一个突触效能净减少CA1下面的液压冲击伤（FPI）。 C:输入/输出曲线描绘净增加突触效能海马齿状回（DG）FPI。 （*表示P &lt;0.05）。 <a href="http://www.jove.com/files/ftp_upload/4411/4411fig3large.jpg" target="_blank">点击此处查看大图</a> 。 <img alt="图4" src="/files/ftp_upload/4411/4411fig4.jpg" /> 图4。代表全细胞膜片钳数据。答:一个例子自发从CA1锥体细胞兴奋性突触后电流（sEPSC的）。 B:从CA1锥体细胞（上迹线）和快速扣球:CA1 interneuron（下迹线）的动作电位火车的。 C:示例的荧光黄充斥CA1抑制性。注意树突棘（上面板）的情况下。 D:荧光黄的实例充满CA1锥体神经元。注意存在的树突棘（上图）。 <a href="http://www.jove.com/files/ftp_upload/4411/4411fig4large.jpg" target="_blank">点击这里查看大图</a> 。 <img alt="图5" src="/files/ftp_upload/4411/4411fig5.jpg" /> 图5。代表电压敏感染料成像数据。答:鼠标冠海马脑片显示，以解剖。 （DG:齿状回，CA1:考纽Ammonis 1）B:黄色至红色像素CA1区14毫秒后传入刺激Schaffer侧支代表兴奋性活动。红中dicates更多的去极化，而黄色表示低，但仍然显着的去极化。 C:蓝色像素代表网站的抑制活性CA1区56毫秒后，同样的传入刺激Schaffer侧支B.深蓝色的表示更多的超极化。

<ol>
	<li>Faul, M., Xu, L., Wald, M. M., Coronado, V. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Traumatic+Brain+Injury+in+the+United+States:+Emergency+Department+Visits+Hospitalizations+and+Deaths+2002-2006.">Traumatic Brain Injury in the United States: Emergency Department Visits Hospitalizations and Deaths 2002-2006.</a> Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. , (2010).</li><li>McAllister, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuropsychiatric+sequelae+of+head+injuries.">Neuropsychiatric sequelae of head injuries.</a> Psychiatr. Clin. North Am. 15, 395-413 (1992).</li><li>Pierce, J. E., Smith, D. H., Trojanowski, J. Q., McIntosh, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enduring+cognitive,+neurobehavioral+and+histopathological+changes+persist+for+up+to+one+year+following+severe+experimental+brain+injury+in+rats.">Enduring cognitive, neurobehavioral and histopathological changes persist for up to one year following severe experimental brain injury in rats.</a> NSC. 87, 359-369 (1998).</li><li>Dixon, C. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+fluid+percussion+model+of+experimental+brain+injury+in+the+rat.">A fluid percussion model of experimental brain injury in the rat.</a> J. Neurosurg. 67, 110-119 (1987).</li><li>McIntosh, T. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Traumatic+brain+injury+in+the+rat:+characterization+of+a+lateral+fluid-percussion+model.">Traumatic brain injury in the rat: characterization of a lateral fluid-percussion model.</a> Neuroscience. 28, 233-244 (1989).</li><li>Carbonell, W. S., Grady, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+and+temporal+characterization+of+neuronal,+glial,+and+axonal+response+after+traumatic+brain+injury+in+the+mouse.">Regional and temporal characterization of neuronal, glial, and axonal response after traumatic brain injury in the mouse.</a> Acta Neuropathol. 98, 396-406 (1999).</li><li>Toth, Z., Hollrigel, G. S., Gorcs, T., Soltesz, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Instantaneous+perturbation+of+dentate+interneuronal+networks+by+a+pressure+wave-transient+delivered+to+the+neocortex.">Instantaneous perturbation of dentate interneuronal networks by a pressure wave-transient delivered to the neocortex.</a> J. Neurosci. 17, 8106-8117 (1997).</li><li>D'Ambrosio, R., Maris, D. O., Grady, M. S., Winn, H. R., Janigro, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+loss+of+hippocampal+long-term+potentiation,+but+not+depression,+following+fluid+percussion+injury.">Selective loss of hippocampal long-term potentiation, but not depression, following fluid percussion injury.</a> Brain Res. 786, 64-79 (1998).</li><li>Witgen, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+hippocampal+alteration+associated+with+cognitive+deficit+following+experimental+brain+injury:+A+systems,+network+and+cellular+evaluation.">Regional hippocampal alteration associated with cognitive deficit following experimental brain injury: A systems, network and cellular evaluation.</a> Neuroscience. 133, 1-15 (2005).</li><li>Schwarzbach, E., Bonislawski, D. P., Xiong, G., Cohen, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+underlying+the+inability+to+induce+area+CA1+LTP+in+the+mouse+after+traumatic+brain+injury.">Mechanisms underlying the inability to induce area CA1 LTP in the mouse after traumatic brain injury.</a> Hippocampus. 16, 541-550 (2006).</li><li>Cole, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dietary+branched+chain+amino+acids+ameliorate+injury-induced+cognitive+impairment.">Dietary branched chain amino acids ameliorate injury-induced cognitive impairment.</a> Proceedings of the National Academy of Sciences. 107, 366-371 (2010).</li></ol>

没有利益冲突的声明。

上面列出的每个技术有助于更​​深入的了解所观察到的行为赤字的内在机制造成的。通过结合从每个方法所取得的固有信息，我们能够检查更精确的生物学机制。 测量的fEPSPs是有用的为大，空间定义的区域的神经元量化净突触的功效。它也可以提供信息的一组细胞的潜力，经过突触可塑性，学习和记忆的神经相关的。这是一个非常有用的，因为它是第一点的电生理分析技?...

<table border="1"><tbody><tr><td> 的设备名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论（可选） </td></tr><tr><td> Axopatch 200B中放大器</td><td> Molecular Devices公司</td><td> Axopatch 200B中</td><td>膜片钳钻机</td></tr><tr><td> Digidata 1322A数字转换器</td><td> Molecular Devices公司</td><td></td><td>膜片钳钻机</td></tr><tr><td> MP-225微操作机器人</td><td>萨特</td><td> MP-225 </td><td>膜片钳钻机</td></tr><tr><td> DMLFSA显微镜</td><td>徕卡</td><td></td><td>膜片钳钻机</td></tr><tr><td> Multiclamp 700B放大器</td><td> Molecular Devices公司</td><td> MULTICLAMP 700B </td><td>多用途（场）操纵</td></tr><tr><td> Digidata 1440数字化仪</td><td> Molecular Devices公司</td><td></td><td> Multipurpos（场）钻机</td></tr><tr><td> MPC-200的微操作机器人</td><td>萨特</td><td> MPC-200 </td><td>多用途（场）钻机</td></tr><tr><td> BX51WI显微镜</td><td>奥林巴斯</td><td> BX51WI </td><td>多用途（场）钻机</td></tr><tr><td> Axoclamp 900A放大器</td><td> Molecular Devices公司</td><td> AXOCLAMP 900A </td><td> VSD钻机</td></tr><tr><td> Digidata 1322数字化仪</td><td> Molecular Devices公司</td><td></td><td> VSD钻机</td></tr><tr><td>红衫CCD-SMQ相机</td><td>红衫</td><td> NCS01 </td><td> VSD钻机</td></tr><tr><td> VT 1200S Vibratome </td><td>徕卡</td> &lt;TD&gt; 14048142066 </td><td></td></tr><tr><td> P-30电极牵拉</td><td>萨特</td><td> P-30 / P </td><td></td></tr><tr><td>完整的蛋白酶抑制剂</td><td>罗氏公司</td><td> 11697498001 </td><td></td></tr></tbody></table>

investigations on alterations of hippocampal circuit function following mild traumatic brain injury

创伤性脑损伤（TBI）折磨着每年超过170万人在美国，即使是轻微的脑外伤可能会导致持久性神经损伤1。普及和禁用的症状所经历的TBI幸存者，记忆障碍和减少癫痫发作阈值，被认为是介导的海马脑外伤引起的功能障碍2,3。为了演示如何改变伤后在小鼠海马的电路功能造成不利影响的行为，我们采用横向液压冲击伤，常用的TBI动物模型，再现了人类TBI的许多功能，包括神经细胞的损失，胶质细胞增生和离子扰动4 - 6。 在这里，我们展示了一个组合的方法调查TBI对海马功能障碍。我们的方法集成了多种体外生理技术结合起来，与动物行为学和生化分析，以分析在海马-TBI后的变化。我们开始实验的伤害模式与行为分析，评估认知障碍，脑外伤。接下来，我们提供三个不同的体外记录技术:外场势记录，可视化全细胞膜片夹紧，和对电压敏感染料记录。最后，我们展示了次区域的海马-TBI后的神经化学和代谢变化的详细分析，可用于区域解剖的方法。 这些方法已被用于检查修改后的海马电路TBI和探测对方在网络电路功能的变化发生在齿状回的海马CA1次区域（ 见图1）。分析后TBI在各次区域的能力是必不可少的理解基本的机制，促进脑外伤引起的行为和认知ðeficits。 这里列出的多面性的系统，使调查人员推过去的表征现象引起的一种疾病状态（在这种情况下，TBI），并确定负责与TBI所观察到的病理机制。

Watch this Scientific Journal Video about Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury at JoVE.com

Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury

一个多层面的方式来调查海马电路的功能变化进行了解释。电技术，以及受伤的协议，行为检测和区域的清扫方法。可以应用这些技术的组合，以类似的方式用于其他大脑区域和科学问题。

调查轻度创伤性脑损伤海马电路功能的改变

Traumatic Brain Injury (TBI) afflicts more than 1.7 million people in the United States each year and even mild TBI can lead to persistent neurological ...

investigations-on-alterations-hippocampal-circuit-function-following

Research

JoVE Journal

Neuroscience

15.2K 次观看.  Children's Hospital of Philadelphia. 一个多层面的方式来调查海马电路的功能变化进行了解释。电技术，以及受伤的协议，行为检测和区域的清扫方法。可以应用这些技术的组合，以类似的方式用于其他大脑区域和科学问题。

视频: Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury

Effects of Blast-induced Neurotrauma on Pressurized Rodent Middle Cerebral Arteries

Though there have been studies on the histopathological and behavioral effects of blast exposure, fewer have been dedicated to blast&#39;s cerebral vascular effects. Impact (i.e., non-blast) traumatic brain injury (TBI) is known to decrease pressure autoregulation in the cerebral vasculature in both humans and experimental animals. The hypothesis that blast-induced traumatic brain injury (bTBI), like impact TBI, results in impaired cerebral vascular reactivity was tested by measuring myogenic dilatory responses to reduced intravascular pressure in rodent middle cerebral arterial (MCA) segments from rats subjected to mild bTBI using an Advanced Blast Simulator (ABS) shock tube. Adult, male Sprague-Dawley rats were anesthetized, intubated, ventilated and prepared for Sham bTBI (identical manipulation and anesthesia except for blast injury) or mild bTBI. Rats were randomly assigned to receive Sham bTBI or mild bTBI followed by sacrifice 30 or 60 min post-injury. Immediately after bTBI, righting reflex (RR) suppression times were assessed, euthanasia at the time points post-injury was completed, the brain was harvested and the individual MCA segments were collected, mounted and pressurized. As the intraluminal pressure perfused through the arterial segments was reduced in 20 mmHg increments from 100 to 20 mmHg, MCA diameters were measured and recorded. With decreasing intraluminal pressure, MCA diameters steadily increased significantly above baseline in the Sham bTBI groups while MCA dilator responses were significantly reduced (p &#60; 0.05) in both bTBI groups as evidenced by the impaired, smaller MCA diameters recorded for the bTBI groups. In addition, RR suppression in the bTBI groups was significantly (p &#60; 0.05) higher than in the Sham bTBI groups. MCA&#39;s collected from the Sham bTBI groups exhibited typical vasodilatory properties to decreases in intraluminal pressure while MCA&#39;s collected following bTBI exhibited significantly impaired myogenic vasodilatory responses to reduced pressure that persisted for at least 60 min after bTBI.

Here, we present a protocol to describe methods for ex vivo vascular reactivity determination following a primary blast traumatic brain injury (bTBI) using isolated, pressurized, rodent middle cerebral arterial (MCA) segments. bTBI induction is accomplished using a shock tube, also known as an Advanced Blast Simulator (ABS) device.

爆炸性神经损伤对压生啮鼠中脑动脉的影响

Though there have been studies on the histopathological and behavioral effects of blast exposure, fewer have been dedicated to blast&#39;s cerebral ...

科研

神经科学

Investigating Alterations in Caecum Microbiota After Traumatic Brain Injury in Mice

Increasing evidence shows that the microbiota-gut-brain axis plays an important role in the pathogenesis of brain diseases. Several studies also demonstrate that traumatic brain injuries cause changes to the gut microbiota. However, mechanisms underlying the bidirectional regulation of the brain-gut axis remain unknown. Currently, few models exist for studying the changes in gut microbiota after traumatic brain injury. Therefore, the presented study combines protocols for inducing traumatic brain injury using a lateral fluid percussion device and analysis of caecum samples following injury for investigating alterations in the gut microbiome. Alterations of the gut microbiota composition after traumatic brain injury are determined using 16S-rDNA sequencing. This protocol provides an effective method for studying the relationships between enteric microorganisms and traumatic brain injury.

Presented here is a protocol to induce diffuse traumatic brain injury using a lateral fluid percussion device followed by the collection of the caecum content for gut microbiome analysis.

研究小鼠创伤性脑损伤后凯库姆微生物群的改动

Increasing evidence shows that the microbiota-gut-brain axis plays an important role in the pathogenesis of brain diseases. Several studies also ...

Advanced Diffusion Imaging in The Hippocampus of Rats with Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) is the most common type of acquired brain injury. Since patients with traumatic brain injury show a tremendous variability and heterogeneity (age, gender, type of trauma, other possible pathologies, etc.), animal models play a key role in unraveling factors that are limitations in clinical research. They provide a standardized and controlled setting to investigate the biological mechanisms of injury and repair following TBI. However, not all animal models mimic the diffuse and subtle nature of mTBI effectively. For example, the commonly used controlled cortical impact (CCI) and lateral fluid percussion injury (LFPI) models make use of a craniotomy to expose the brain and induce widespread focal trauma, which are not commonly seen in mTBI. Therefore, these experimental models are not valid to mimic mTBI. Thus, an appropriate model should be used to investigate mTBI. The Marmarou weight drop model for rats induces similar microstructural alterations and cognitive impairments as seen in patients who sustain mild trauma; therefore, this model was selected for this protocol. Conventional computed tomography and magnetic resonance imaging (MRI) scans commonly show no damage following a mild injury, because mTBI induces often only subtle and diffuse injuries. With diffusion weighted MRI, it is possible to investigate microstructural properties of brain tissue, which can provide more insight into the microscopic alterations following mild trauma. Therefore, the goal of this study is to obtain quantitative information of a selected region-of-interest (i.e., hippocampus) to follow up disease progression after obtaining a mild and diffuse brain injury.

The overall goal of this procedure is to obtain quantitative microstructural information of the hippocampus in a rat with mild traumatic brain injury. This is done using an advanced diffusion-weighted magnetic resonance imaging protocol and region-of-interest based analysis of parametric diffusion maps.

轻度创伤性脑损伤大鼠海马学的高级扩散成像

Mild traumatic brain injury (mTBI) is the most common type of acquired brain injury. Since patients with traumatic brain injury show a tremendous ...

Low-intensity Blast Wave Model for Preclinical Assessment of Closed-head Mild Traumatic Brain Injury in Rodents

Traumatic brain injury (TBI) is a large-scale public health problem. Mild TBI is the most prevalent form of neurotrauma and accounts for a large number of medical visits in the United States. There are currently no FDA-approved treatments available for TBI. The increased incidence of military-related, blast-induced TBI further accentuates the urgent need for effective TBI treatments. Therefore, new preclinical TBI animal models that recapitulate aspects of human blast-related TBI will greatly advance the research efforts into the neurobiological and pathophysiological processes underlying mild to moderate TBI as well as the development of novel therapeutic strategies for TBI.
Here we present a reliable, reproducible model for the investigation of the molecular, cellular, and behavioral effects of mild to moderate blast-induced TBI. We describe a step-by-step protocol for closed-head, blast-induced mild TBI in rodents using a bench-top setup consisting of a gas-driven shock tube equipped with piezoelectric pressure sensors to ensure consistent test conditions. The benefits of the setup that we have established are its relative low-cost, ease of installation, ease of use and high-throughput capacity. Further advantages of this non-invasive TBI model include the scalability of the blast peak overpressure and the generation of controlled reproducible outcomes. The reproducibility and relevance of this TBI model has been evaluated in a number of downstream applications, including neurobiological, neuropathological, neurophysiological and behavioral analyses, supporting the use of this model for the characterization of processes underlying the etiology of mild to moderate TBI.

We present here a protocol of a blast wave model for rodents to investigate neurobiological and pathophysiological effects of mild to moderate traumatic brain injury. We established a gas-driven, bench-top setup equipped with pressure sensors allowing for reliable and reproducible generation of blast-induced mild to moderate traumatic brain injury.

低强度冲击波模型用于啮齿动物闭头轻度创伤性脑损伤的临床前评估

Traumatic brain injury (TBI) is a large-scale public health problem. Mild TBI is the most prevalent form of neurotrauma and accounts for a large number of ...

Electromagnetic Controlled Closed-Head Model of Mild Traumatic Brain Injury in Mice

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and understanding the mechanisms of how a TBI alters brain function. The availability of multiple animal models of TBI is necessary to model the different aspects and severities of TBI seen in people. This manuscript describes the use of a midline closed head injury (CHI) to develop a mouse model of mild TBI. The model is considered mild because it does not produce structural brain lesions based on neuroimaging or gross neuronal loss. However, a single impact creates enough pathology that cognitive impairment is measurable at least 1 month after injury. A step-by-step protocol to induce a CHI in mice using a stereotaxically guided electromagnetic impactor is defined in the paper. The benefits of the mild midline CHI model include the reproducibility of the injury-induced changes with low mortality. The model has been temporally characterized up to 1 year after the injury for neuroimaging, neurochemical, neuropathological, and behavioral changes. The model is complementary to open skull models of controlled cortical impact using the same impactor device. Thus, labs can model both mild diffuse TBI and focal moderate-to-severe TBI with the same impactor.

The protocol describes mild traumatic brain injury in a mouse model. In particular, a step-by-step protocol to induce a mild midline closed head injury and the characterization of the animal model is fully explained.

小鼠轻度创伤性脑损伤的电磁控制闭头模型

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and ...

Assessing Changes in Synaptic Plasticity Using an Awake Closed-Head Injury Model of Mild Traumatic Brain Injury

Mild traumatic brain injuries (mTBIs) are a prevalent health issue in North America. There is increasing pressure to utilize ecologically valid models of closed-head mTBI in the preclinical setting to increase translatability to the clinical population. The awake closed-headed injury (ACHI) model uses a modified controlled cortical impactor to deliver closed-headed injury, inducing clinically relevant behavioral deficits without the need for a craniotomy or the use of an anesthetic.
This technique does not normally induce fatalities, skull fractures, or brain bleeds, and is more consistent with being a mild injury. Indeed, the mild nature of the ACHI procedure makes it ideal for studies investigating repetitive mTBI (r-mTBI). Growing evidence indicates that r-mTBI can result in a cumulative injury that produces behavioral symptoms, neuropathological changes, and neurodegeneration. r-mTBI is common in youths playing sports, and these injuries occur during a period of robust synaptic reorganization and myelination, making the younger population particularly vulnerable to the long-term influences of r-mTBI.
Further, r-mTBI occurs in cases of intimate partner violence, a condition for which there are few objective screening measures. In these experiments, synaptic function was assessed in the hippocampus in juvenile rats that had experienced r-mTBI using the ACHI model. Following the injuries, a tissue slicer was utilized to make hippocampal slices to evaluate bidirectional synaptic plasticity in the hippocampus at either 1 or 7 days following the r-mTBI. Overall, the ACHI model provides researchers with an ecologically valid model to study changes in synaptic plasticity following mTBI and r-mTBI.

Here, it is demonstrated how an awake closed-head injury model can be used for examining the effects of repeated mild traumatic brain injury (r-mTBI) on synaptic plasticity in the hippocampus. The model replicates important features of r-mTBI in patients and is used in conjunction with in vitro electrophysiology.

使用轻度创伤性脑损伤的清醒闭合性头部损伤模型评估突触可塑性的变化

Mild traumatic brain injuries (mTBIs) are a prevalent health issue in North America. There is increasing pressure to utilize ecologically valid models of ...

在 mTBI 大鼠模型中验证损伤反应和行为评估

Rat Model of Closed-Head Mild Traumatic Injury and its Validation

Animal models are crucial for advancing our understanding of mild traumatic brain injury (mTBI) and guiding clinical research. To achieve meaningful insights, developing a stable and reproducible animal model is essential. In this study, we report a detailed description of a closed-head mTBI model and a representative validation method using Sprague-Dawley rats to verify the modeling effect. The model involves dropping a 550 g mass weight from a height of 100 cm directly onto the head of a rat on a destructible surface, followed by a 180-degree turn. To assess the injury, rats underwent a series of neurobehavioral assessments 10 min post-injury, including time of loss of consciousness, first seeking-behavior time, escape ability, and beam balance ability test. During the acute and subacute stages following the injury, behavioral tests were conducted to assess motor coordination ability (Beam task), anxiety (Open Field test), and learning and memory abilities (Morris Water Maze test). The closed-head mTBI model produced a consistent injury response with minimal mortality and replicated real-life situations. The validation method effectively verified the model development and ensured the stability and consistency of the model.

作者聚焦:推进创伤性脑损伤研究 - 用于准确复制和快速评估的闭头模型 

Here, we present a closed-head mild traumatic brain injury (mTBI) rat model and its validation exhibiting remarkable similarity to human mTBI concerning behavioral manifestations during the acute and subacute stages.

闭合头轻度创伤大鼠模型及其验证

Animal models are crucial for advancing our understanding of mild traumatic brain injury (mTBI) and guiding clinical research. To achieve meaningful ...

通过闭合头部损伤法在小鼠中诱导 rmTBI

Modified Mouse Model of Repetitive Mild Traumatic Brain Injury Incorporating Thinned-Skull Window and Fluid Percussion

Mild traumatic brain injury is a clinically highly heterogeneous neurological disorder. Highly reproducible traumatic brain injury (TBI) animal models with well-defined pathologies are urgently needed for studying the mechanisms of neuropathology after mild TBI and testing therapeutics. Replicating the entire sequelae of TBI in animal models has proven to be a challenge. Therefore, the availability of multiple animal models of TBI is necessary to account for the diverse aspects and severities seen in TBI patients. CHI is one of the most common methods for fabricating rodent models of rmTBI. However, this method is susceptible to many factors, including the impact method used, the thickness and shape of the skull bone, animal apnea, and the type of head support and immobilization utilized. The aim of this protocol is to demonstrate a combination of the thinned-skull window and fluid percussion injury (FPI) methods to produce a precise mouse model of CHI-associated rmTBI. The primary objective of this protocol is to minimize factors that could impact the accuracy and consistency of CHI and FPI modeling, including skull bone thickness, shape, and head support. By utilizing a thinned-skull window method, potential inflammation due to craniotomy and FPI is minimized, resulting in an improved mouse model that replicates the clinical features observed in patients with mild TBI. Results from behavior and histological analysis using hematoxylin and eosin (HE) staining suggest that rmTBI can lead to a cumulative injury that produces changes in both behavior and gross morphology of the brain. Overall, the modified CHI-associated rmTBI presents a useful tool for researchers to explore the underlying mechanisms that contribute to focal and diffuse pathophysiological changes in rmTBI.

作者聚焦:优化啮齿动物模型以研究反复轻度创伤性脑损伤的机制和康复

This protocol presents a modified mouse model of repetitive mild traumatic brain injury (rmTBI) induced via a closed-head injury (CHI) method. The approach features a thinned-skull window and fluid percussion to reduce the inflammation commonly caused by meninges exposure, along with improved reproducibility and accuracy in modeling rmTBI in rodents.

结合颅骨窗变薄和液体叩击的重复性轻度创伤性脑损伤改良小鼠模型

Mild traumatic brain injury is a clinically highly heterogeneous neurological disorder. Highly reproducible traumatic brain injury (TBI) animal models ...

Methods Article

调查轻度创伤性脑损伤海马电路功能的改变