我们要感谢中南大学实验动物系的所有研究员。本研究得到了国家自然科学基金（第81971791号）的支持;法医学上海市重点实验室， 法医学部重点实验室（法医学研究院）KF202104）。

动物实验由中南大学动物护理和使用委员会批准。所有研究均按照实验动物的福利和伦理原则进行。
1.动物喂养和麻醉程序
<ol><li>群居280-320克Sprague-Dawley雄性大鼠，并将它们维持在12小时/ 12小时的光/暗循环中， 并随意获得食物和水。在大鼠适应环境6天后进行研究。</li>
	<li>在诱导箱中以0.6L / min的气流用3%异氟醚麻醉大鼠，直到它对爪子或尾巴捏没有反应。保持流速30秒。 注意：不使用止痛药，因为它们会干扰大鼠在神经行为评估中的反应。</li>
</ol>2. 术前设置
<ol><li>将硬度值为 35D（海绵重量为 35 kg/m3）的海绵放置在没有顶盖的亚克力盒 （15 cm x 22 cm x 43 cm） 中，长度和宽度相同，但厚度为 12 cm。</li>
	<li>修剪锡箔（厚度为20μm）并使用胶带将其固定在亚克力盒上，以形成能够支撑大鼠重量的可破坏表面。此外，标记一条大约 10 厘米的切割线作为定位大鼠头部的指定位置。</li>
	<li>借助铁架，将 PVC 管牢固地固定到位。准备一个穿孔砝码，重 550 克，直径为 18 毫米。将重物连接到聚氯乙烯或 PVC 管内 1 米高的钓鱼线上。并将导管的位置调整到锡箔上方 3 厘米处。</li>
	<li>准备头盔和枕头。使用直径为 10 毫米、厚度为 3 毫米的不锈钢圆盘制作头盔。准备一个楔形海绵枕头放在老鼠的头部下方，确保它垂直于重力方向。 注： 冲击装置的示意图如 图 1 所示。头盔的作用是识别撞击位置并增强外力的分布。枕头用于保证均匀稳定的损坏。</li>
</ol>3. mTBI诱导
<ol><li>迅速将麻醉的大鼠放在锡箔纸上的胸部。 注意：mTBI 诱导需要两名操作员 - 一名用于准备，另一名用于验证。</li>
	<li>准备：将枕头放在老鼠下面，确保其头部与铝箔纸平行。将头盔与老鼠的耳朵对齐并将其固定到位。</li>
	<li>验证：验证 PVC 管是否位于头盔的正上方。两个操作员确认设置正确后，继续下一步。</li>
	<li>诱导头部旋转：释放重物，让它下落并撞击大鼠的头部，导致跌落到海绵上并旋转 180°。</li>
	<li>将老鼠放在干净的笼子里。</li>
</ol>4. 假诱导
<ol><li>以与先前mTBI诱导描述相同的方式对待大鼠，但不要使其受到头部撞击。</li>
</ol>5. 验证程序：急性神经行为评估
注意：以下评估是根据 Flierl 等人 10 的神经严重程度评分9 和协议修改的。所有这些评估都是在大鼠恢复矫正反射后 10 分钟进行的。
<ol><li>意识丧失时间：记录从大鼠被麻醉到恢复矫正反射的持续时间。 注意：矫正反射是大鼠仰卧时翻身的过程。矫正反射的丧失应被视为人道的终点，并且必须按照机构指南对动物实施安乐死。</li>
	<li>第一次寻找行为时间：记录从大鼠被麻醉到第一次出现寻找行为的持续时间。 注意：寻求行为是对环境感兴趣的标志，是一种生理反应。</li>
	<li>逃生能力<ol><li>将大鼠放在带有出口（长12.5厘米，宽9厘米）的圆形装置（直径0.5米，高0.3米）的中间。</li>
		<li>记录老鼠离开圆圈所需的时间。 注意：如果大鼠在180秒内没有离开圆圈，则将时间记录为180秒。</li>
	</ol></li>
	<li>光束平衡能力测试<ol><li>将大鼠放在3cm，2cm和1.5cm宽的光束上1分钟。</li>
		<li>如果大鼠在横梁上保持平衡，保持稳定姿势，则将其打为 0。</li>
		<li>如果老鼠抓住横梁的一侧，则给 1 分。如果老鼠抱住横梁，一只肢体从横梁上掉下来，则将其打成 2。</li>
		<li>如果老鼠拥抱横梁，两肢从横梁上掉下来或在上面旋转（>60 秒），则将其打成 3。</li>
		<li>如果大鼠试图在横梁上保持平衡但掉下来（> 40 秒），则将其打成 4。</li>
		<li>如果大鼠试图在横梁上保持平衡但掉下来（>20 秒），则将其打成 5。</li>
		<li>如果老鼠没有试图平衡或挂在横梁上并在 20 秒内掉下来，则将其打为 6。 注意：光束平衡测试不需要预试验。</li>
	</ol></li>
</ol>6. 验证程序：神经行为评估
注意：在行为实验之前，连续3天每天处理大鼠2分钟，以尽量减少压力和新奇性干扰。所有行为实验都是通过在实验开始前将动物置于测试环境中 60 分钟来进行的。
<ol><li>运动协调能力（光束任务）<ol><li>实验装置<ol><li>将大鼠放在平衡木的一端（长1.5 m，离地面75厘米）。在另一端放置一个逃生箱（倾斜的床上用品家庭笼子）。</li>
			<li>在横梁下方放置泡沫衬垫，以减轻在测试过程中跌倒时对大鼠造成伤害的潜在风险。</li>
			<li>打开摄像机。</li>
			<li>将检测日安排在受伤后或假治疗后的特定时间点（例如，第 1 天、第 3 天和第 7 天）。</li>
		</ol></li>
		<li>培训阶段（2天）<ol><li>训练大鼠连续 3 次穿过 4 厘米宽的光束，然后在 2 厘米宽的光束上进行两次试验。</li>
			<li>在训练过程中，轻轻地引导老鼠穿过光束，直到它们可以不受干扰地轻松穿过光束。</li>
		</ol></li>
		<li>平衡木实验<ol><li>将大鼠放在2厘米宽的光束上连续5次试验。</li>
			<li>当大鼠的鼻子分别越过起点和终点线时，记录每次试验的开始和结束。</li>
			<li>在实验结束时将大鼠放回笼子。</li>
		</ol></li>
		<li>基线测试<ol><li>在受伤或治疗前进行平衡木实验。</li>
			<li>计算这 5 次连续试验的平均值，以建立每只大鼠的基线。</li>
		</ol></li>
		<li>数据分析<ol><li>使用对实验条件不知情的研究人员的视频分析，分析穿过横梁的时间和后足滑倒的总数。</li>
		</ol></li>
	</ol></li>
	<li>焦虑（开放场测试）<ol><li>实验装置<ol><li>准备空旷的场地，确保它干净，没有任何以前的气味提示。将竞技场分为三个区域：中央内区（33 cm x 33 cm）、中间区（66 cm x 66 cm）和外区。</li>
		</ol></li>
		<li>测试阶段<ol><li>将一只老鼠放在空旷场地的中央并启动计时器。让老鼠自由探索竞技场 5 分钟。5分钟后，小心轻轻地将老鼠放回笼子里。</li>
		</ol></li>
		<li>数据采集<ol><li>测量大鼠在 5 分钟的探索期间行进的总距离。确定大鼠在中央内区、中区和外区停留的时间。</li>
		</ol></li>
		<li>数据分析<ol><li>使用行进的总距离作为整体探索行为和运动能力的衡量标准。计算在中央内区花费的时间，作为焦虑样反应的指标。</li>
		</ol></li>
	</ol></li>
	<li>学习和记忆能力（莫里斯水迷宫测试）<ol><li>确保水迷宫设备处于正常状态。将水染成黑色，并在四个基本方向上放置提示。将平台放置在水面以下 2.5 厘米处。</li>
		<li>设置监控系统来记录和观察老鼠的行为。</li>
		<li>步道日<ol><li>迅速将老鼠放入水迷宫中。如果老鼠未能在2分钟内到达平台，请用木棍轻轻引导它。</li>
			<li>让老鼠在平台上站立 20 秒时熟悉迷宫环境，然后将其移除。一旦老鼠在平台上，让它停留 20 秒，然后将其移除。</li>
		</ol></li>
		<li>每日重复<ol><li>重复训练日程序，将大鼠放入不同象限的水中。重复步骤 6.3.3。连续 5 天继续训练。</li>
		</ol></li>
		<li>探针测试日：在第 6天，取下平台并将大鼠置于同一象限2分钟。</li>
		<li>观察和记录：利用监测系统监测大鼠在试验和探测测试日的行为。</li>
		<li>清洁：将老鼠从水迷宫中取出后，用毛巾彻底擦干。</li>
	</ol></li>
</ol>

在 mTBI 大鼠模型中验证损伤反应和行为评估

<ol>
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作者没有经济利益需要披露。

该模型成功地模拟了闭合的头部 mTBI，而无需头皮切口或颅骨开口，从而更准确地表示了在人类病例中观察到的撞击场景。避免头皮切口有助于防止可能与实际情况不符的炎症反应。与 Richelle Mychasiuk 的儿科模型12 相比，本研究中使用的模型专为体重在 280-320 g 之间的成年大鼠量身定制，使我们能够获得对 mTBI 对成年个体影响的宝贵见解。此外，结合枕头和头盔等关键部件有助于?...

轻度创伤性脑损伤 （mTBI） 或脑震荡是最普遍的损伤类型，可导致各种短期和慢性症状1。这些症状可能包括头晕、头痛、抑郁和快感缺乏等，导致受 mTBI2 影响的个体遭受重大痛苦。由于大多数 mTBI 是由钝器外伤引起的 3，因此必须开发准确模拟此类损伤的动物模型。这些模型对于更好地了解损伤及其潜在机制至关重要，与人类研究相比，提供了一个可控的环境，减少了变异性和异质性。
已经开发了许多成熟的啮齿动物模型来治疗创伤性脑损伤 （TBI），包括液体叩击损伤 （FPI）4、受控皮质冲击 （CCI）5、体重下降损伤6、爆炸性创伤性脑损伤7 等。然而，这些模型主要侧重于复制中度至重度 TBI 情景。相比之下，专门设计用于模拟 mTBI 的实验模型受到的关注相对较少，并且仍未得到充分探索8。因此，迫切需要建立一个稳定且可重复的动物模型，以准确表示mTBI。这样的模型将显着增强我们对与 mTBI 相关的神经生物学和行为后果的理解。
在麻醉效果消失后，人们无法通过随意观察来区分mTBI大鼠与正常大鼠的功能缺陷。因此，有必要进行特定的测试。在人类中，广泛的临床评估用于评估患者 9,10,11。同样，在大鼠模型中建立一个成功的模型也需要使用快速评估工具来确定其有效性。
在这项研究中，我们提出了一个闭头mTBI大鼠模型，能够以与人类状况非常相似的方式研究mTBI。对模型及其验证程序的详细描述提供了对研究 mTBI 所用实验方法的全面理解。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Acrylic box</td>
			<td>In-house</td>
			<td>N/A</td>
			<td>15 cm x 22 cm x 43 cm</td>
		</tr>
		<tr>
			<td>Anesthesia Machine</td>
			<td>RWD Life Science Co.</td>
			<td>R540 Mice &#38; Rat Animal Anesthesia Machine</td>
			<td></td>
		</tr>
		<tr>
			<td>Helmet</td>
			<td>In-house</td>
			<td>N/A</td>
			<td>Stainless-steel disk measuring 10 mm in diameter and 3 mm in thickness</td>
		</tr>
		<tr>
			<td>Morris water maze</td>
			<td>RWD Life Science Co.</td>
			<td></td>
			<td>Diameter 150 cm, height 50 cm,platform diameter 35 cm</td>
		</tr>
		<tr>
			<td>Open field</td>
			<td>RWD Life Science Co.</td>
			<td>63007</td>
			<td>Width100 cm, height 40 cm</td>
		</tr>
		<tr>
			<td>Panlab SMART V3.0</td>
			<td>RWD Life Science Co.</td>
			<td>SMART v3.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Perforated weight</td>
			<td>In-house</td>
			<td>N/A</td>
			<td>Weight of 550 g and diameter of 18 mm</td>
		</tr>
		<tr>
			<td>Pillow</td>
			<td>In-house</td>
			<td>N/A</td>
			<td>Wedge-shaped sponge to place beneath the rat&#39;s head</td>
		</tr>
	</tbody>
</table>

rat model of closed-head mild traumatic injury and its validation

动物模型对于促进我们对轻度创伤性脑损伤 （mTBI） 的理解和指导临床研究至关重要。为了获得有意义的见解，开发稳定且可重复的动物模型至关重要。在这项研究中，我们报告了闭头 mTBI 模型的详细描述以及使用 Sprague-Dawley 大鼠验证建模效果的代表性验证方法。该模型涉及将 550 克的质量砝码从 100 厘米的高度直接落到可破坏表面上的大鼠头部，然后进行 180 度转弯。为了评估损伤，大鼠在受伤后 10 分钟接受了一系列神经行为评估，包括意识丧失时间、首次寻找行为时间、逃生能力和光束平衡能力测试。在受伤后的急性和亚急性阶段，进行行为测试以评估运动协调能力（光束任务）、焦虑（开放场地测试）以及学习和记忆能力（莫里斯水迷宫测试）。闭头 mTBI 模型以最低的死亡率产生了一致的损伤反应，并复制了现实生活中的情况。验证方法有效地验证了模型的开发，保证了模型的稳定性和一致性。

这项工作中使用的设备是 Kane 模型和 Richelle Mychasiuk 的儿科模型11,12 的改进版本。在这项研究中，SD大鼠被分配到假手术组和mTBI组。为了证明该模型的可重复性，我们对该模型进行了三次独立重复以及急性神经行为评估，每个实验涉及 8-12 只大鼠。在这项研究中，我们使用了 30 多只 mTBI 大鼠，其中 2 只大鼠因麻醉而死亡。然而?...

Watch this Scientific Journal Video about Advancing Traumatic Brain Injury Research â€” A Closed-Head Model for Accurate Replication and Rapid Assessment at JoVE.com

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 

在这里，我们提出了一个闭合式轻度创伤性脑损伤 （mTBI） 大鼠模型及其验证，在急性和亚急性阶段的行为表现方面与人类 mTBI 表现出显着的相似性。

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 ...

在这项研究中，我们介绍了一个闭头、轻度创伤性脑损伤大鼠模型，并对其验证进行了全面概述。我们的目标是提供一种简单的方法来复制这种类型的脑损伤，并提供一种快速评估方法来确认模型的成功。该模型成功地模拟了闭合的头部、轻度创伤性脑损伤，无需头皮切口或颅骨开口，更准确地表示了在人类病例中观察到的撞击场景。避免头皮切口有助于防止可能与活动情况不一致的炎症反应。轻度创伤性脑损伤缺乏主观和准确的诊断方法。未来，我们的实验室将继续探索可能的生物分子标志物及其深层分子机制，并帮助将获得的分子标记物转化为临床和法医鉴定实践。

rat-model-of-closed-head-mild-traumatic-injury-and-its-validation

Research

JoVE Journal

Neuroscience

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

1.0K 次观看.  School of Basic Medical Science, Central South University. 在这项研究中，我们介绍了一个闭头、轻度创伤性脑损伤大鼠模型，并对其验证进行了全面概述。我们的目标是提供一种简单的方法来复制这种类型的脑损伤，并提供一种快速评估方法来确认模型的成功。该模型成功地模拟了闭合的头部、轻度创伤性脑损伤，无需头皮切口或颅骨开口，更准确地表示了在人类病例中观察到的撞击场景。避免头皮切口有助于防止可能与活?...

视频: 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 

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

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 impairments 1. Two pervasive and disabling symptoms experienced by TBI survivors, memory deficits and a reduction in seizure threshold, are thought to be mediated by TBI-induced hippocampal dysfunction 2,3. In order to demonstrate how altered hippocampal circuit function adversely affects behavior after TBI in mice, we employ lateral fluid percussion injury, a commonly used animal model of TBI that recreates many features of human TBI including neuronal cell loss, gliosis, and ionic perturbation 4-6.
	Here we demonstrate a combinatorial method for investigating TBI-induced hippocampal dysfunction. Our approach incorporates multiple ex vivo physiological techniques together with animal behavior and biochemical analysis, in order to analyze post-TBI changes in the hippocampus. We begin with the experimental injury paradigm along with behavioral analysis to assess cognitive disability following TBI. Next, we feature three distinct ex vivo recording techniques: extracellular field potential recording, visualized whole-cell patch-clamping, and voltage sensitive dye recording. Finally, we demonstrate a method for regionally dissecting subregions of the hippocampus that can be useful for detailed analysis of neurochemical and metabolic alterations post-TBI.
	These methods have been used to examine the alterations in hippocampal circuitry following TBI and to probe the opposing changes in network circuit function that occur in the dentate gyrus and CA1 subregions of the hippocampus (see Figure 1). The ability to analyze the post-TBI changes in each subregion is essential to understanding the underlying mechanisms contributing to TBI-induced behavioral and cognitive deficits. 
	The multi-faceted system outlined here allows investigators to push past characterization of phenomenology induced by a disease state (in this case TBI) and determine the mechanisms responsible for the observed pathology associated with TBI.

A multi-faceted approach to investigating functional changes to hippocampal circuitry is explained. Electrophysiological techniques are described along with the injury protocol, behavioral testing and regional dissection method. The combination of these techniques can be applied in similar fashion for other brain regions and scientific questions.

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 ...

科研

神经科学

A Method to Inflict Closed Head Traumatic Brain Injury in Drosophila

Traumatic brain injury (TBI) affects millions of people each year, causing impairment of physical, cognitive, and behavioral functions and death. Studies using Drosophila have contributed important breakthroughs in understanding neurological processes. Thus, with the goal of understanding the cellular and molecular basis of TBI pathologies in humans, we developed the High Impact Trauma (HIT) device to inflict closed head TBI in flies. Flies subjected to the HIT device display phenotypes consistent with human TBI such as temporary incapacitation and progressive neurodegeneration. The HIT device uses a spring-based mechanism to propel flies against the wall of a vial, causing mechanical damage to the fly brain. The device is inexpensive and easy to construct, its operation is simple and rapid, and it produces reproducible results. Consequently, the HIT device can be combined with existing experimental tools and techniques for flies to address fundamental questions about TBI that can lead to the development of diagnostics and treatments for TBI. In particular, the HIT device can be used to perform large-scale genetic screens to understand the genetic basis of TBI pathologies.

A Method to Inflict Closed Head Traumatic Brain Injury in Drosophila

Here we describe a method to inflict closed head traumatic brain injury (TBI) in Drosophila. This method provides a gateway to investigate the cellular and molecular mechanisms that underlie TBI pathologies using the vast array of experimental tools and techniques available for flies.

方法对敌人造成闭合性颅脑创伤性脑损伤<em&gt;果蝇</em

Traumatic brain injury (TBI) affects millions of people each year, causing impairment of physical, cognitive, and behavioral functions and death. Studies ...

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 ...

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 ...

<meta charset="utf8"></head><body>基于荧光染料的小鼠血脑屏障分解可视化

Evaluation of Blood-Brain Barrier Breakdown in a Mouse Model of Mild Traumatic Brain Injury

Fluorescent dyes are used to determine the extent of dye extravasation that occurs due to blood-brain barrier (BBB) breakdown. Labeling with these dyes is a complex process influenced by several factors, such as the concentration of dyes in the blood, permeability of brain vessels, duration of dye extravasation, and reduction in dye concentration in the tissue due to degradation and diffusion. In a mild traumatic brain injury model, exposure to blast-induced shock waves (BSWs) triggers BBB breakdown within a limited time window. To determine the precise sequence of BBB breakdown, Evans blue, and fluorescein isothiocyanate-dextran were injected intravascularly and intracardially into mice at various time points relative to BSW exposure. The distribution of dye fluorescence in brain slices was then recorded. Differences in the distribution and intensity between the two dyes revealed the spatiotemporal sequence of BBB breakdown. Immunostaining of the brain slices showed that astrocytic and microglial responses correlated with the sites of BBB breakdown. This protocol has broad potential for application in studies involving different BBB breakdown models.

<meta charset="utf8"></head><body>轻度创伤性脑损伤小鼠模型中血脑屏障破坏的评价

A method was developed to visualize dye extravasation due to blood-brain barrier (BBB) breakdown by administering two fluorescent dyes to mice at different time points. The use of glycerol as a cryoprotectant facilitated immunohistochemistry on the same sample.

轻度创伤性脑损伤小鼠模型中血脑屏障破坏的评价

Fluorescent dyes are used to determine the extent of dye extravasation that occurs due to blood-brain barrier (BBB) breakdown. Labeling with these dyes is ...

Methods Article

闭合头轻度创伤大鼠模型及其验证