We want to thank all the fellows in the Department of Laboratory Animals of Central South University. This study was supported by the National Natural Science Foundation of China (No. 81971791); Shanghai Key Lab of Forensic Medicine, Key Lab of Forensic Science, Ministry of Justice, China (Academy of Forensic Science) (No. KF202104).

Animal experiments were approved by the Central South University Animal Care and Use Committee. All studies were conducted in line with the welfare and ethical principles of laboratory animals.
1. Animal feeding and anesthetization procedure
<ol>
	<li>Group house 280-320 g Sprague-Dawley male rats and maintain them on a 12 h/12 h light/dark cycle with access to food and water ad libitum. Perform the study after the rats acclimatize for 6 days.</li>
	<li>Anesthetize the rat with 3% i...

Validating Injury Response and Behavioral Assessments in an mTBI Rat Model

<ol>
	<li>Silverberg, N. D., Duhaime, A. C., Iaccarino, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mild+traumatic+brain+injury+in+2019-2020.">Mild traumatic brain injury in 2019-2020.</a> JAMA. 323 (2), 177-178 (2020).</li><li>Kim, K., Priefer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+current+post-concussion+protocols.">Evaluation of current post-concussion protocols.</a> Biomedicine &amp; Pharmacotherapy. 129, 110406 (2020).</li><li>Peeters, W., 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=Epidemiology+of+traumatic+brain+injury+in+Europe.">Epidemiology of traumatic brain injury in Europe.</a> Acta Neurochirurgica (Wien). 157 (10), 1683-1696 (2015).</li><li>Kabadi, S. V., Hilton, G. D., Stoica, B. A., Zapple, D. N., Faden, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluid-percussion-induced+traumatic+brain+injury+model+in+rats.">Fluid-percussion-induced traumatic brain injury model in rats.</a> Nature Protocols. 5 (9), 1552-1563 (2010).</li><li>Smith, D. H., 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+model+of+parasagittal+controlled+cortical+impact+in+the+mouse:+cognitive+and+histopathologic+effects.">A model of parasagittal controlled cortical impact in the mouse: cognitive and histopathologic effects.</a> Journal of Neurotrauma. 12 (2), 169-178 (1995).</li><li>Feeney, D. M., Boyeson, M. G., Linn, R. T., Murray, H. M., Dail, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Responses+to+cortical+injury:+I.+Methodology+and+local+effects+of+contusions+in+the+rat.">Responses to cortical injury: I. Methodology and local effects of contusions in the rat.</a> Brain Research. 211 (1), 67-77 (1981).</li><li>Cernak, I., 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=The+pathobiology+of+blast+injuries+and+blast-induced+neurotrauma+as+identified+using+a+new+experimental+model+of+injury+in+mice.">The pathobiology of blast injuries and blast-induced neurotrauma as identified using a new experimental model of injury in mice.</a> Neurobiology of Disease. 41 (2), 538-551 (2011).</li><li>Shultz, S. R., 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=The+potential+for+animal+models+to+provide+insight+into+mild+traumatic+brain+injury:+Translational+challenges+and+strategies.">The potential for animal models to provide insight into mild traumatic brain injury: Translational challenges and strategies.</a> Neuroscience and Biobehavioral Reviews. 76 (Pt B), 396-414 (2017).</li><li>Chen, J., 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=Therapeutic+benefit+of+intravenous+administration+of+bone+marrow+stromal+cells+after+cerebral+ischemia+in+rats.">Therapeutic benefit of intravenous administration of bone marrow stromal cells after cerebral ischemia in rats.</a> Stroke. 32 (4), 1005-1011 (2001).</li><li>Flierl, M. 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This model successfully simulates a closed-head mTBI without the need for scalp incision or skull opening, providing a more accurate representation of the impact scenario observed in human cases. The avoidance of scalp incision helps prevent inflammatory responses that may not align with the actual situation. Compared to Richelle Mychasiuk's pediatric model12, the model used in this study is specifically tailored for adult rats weighing between 280-320 g, enabling us to obtain valuable insights in...

Mild traumatic brain injury (mTBI), or concussion, is the most prevalent type of injury and can lead to various short-term and chronic symptoms1. These symptoms may include dizziness, headaches, depression, and anhedonia, among others, leading to significant suffering for individuals affected by mTBI2. Since most mTBIs are caused by blunt force trauma3, it becomes imperative to develop animal models that accurately mimic such injuries. These models are essential for gaining a better understanding of the injury and its underlying mechanisms, offering a controlled environment with reduced variability and heterogeneity compared to human studies.
Numerous well-established rodent models have been developed for traumatic brain injury (TBI), including fluid percussion injury (FPI)4, controlled cortical impact (CCI)5, weight-drop injury6, blast traumatic brain injury7, and others. However, these models primarily focus on replicating moderate to severe TBI scenarios. In contrast, the experimental models specifically designed to simulate mTBI have received relatively less attention and remain underexplored8. Therefore, there is a critical need to establish a stable and reproducible animal model that accurately represents mTBI. Such a model would significantly enhance our understanding of the neurobiological and behavioral consequences associated with mTBI.
One cannot distinguish the functional deficits in mTBI rats compared to normal rats via casual observation after the effects of anesthesia have worn off. Therefore, it is necessary to administer specific tests. In humans, a wide range of clinical assessments are used to evaluate patients9,10,11. Similarly, establishing a successful model in the rat model also requires using rapid assessment tools to determine its validity.
In this study, we present a closed-head mTBI rat model, enabling the investigation of mTBI in a manner that closely resembles the human condition. The detailed description of the model and its validation procedure provides a comprehensive understanding of the experimental approach utilized in studying mTBI.

<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

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.

Author Spotlight: Advancing Traumatic Brain Injury Research - A Closed-Head Model for Accurate Replication and Rapid Assessment 

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

In this study, we introduced a closed-head, mild traumatic brain injury rat model, and provided a comprehensive overview of its validation. Our goal was to offer a straightforward approach for replicating this type of brain injury and a rapid assessment method for confirming the success of the model. This model successfully simulates a closed-head, mild traumatic brain injury without the need for scalp incision or skull opening, provide a more accurate representation of the impact scenario observed in human cases.The avoidance of scalp incision helps to prevent inflammatory responses that may not align with the active situation. Mild traumatic brain injury lacks subjective and accurate diagnostic methods. In the future, our laboratory will continue to explore possible biomolecular markers and their deep molecular mechanisms, and help to transform the obtained molecular markers into clinical and forensic identification practices.

The apparatus used in this work was a modified version of the Kane model and Richelle Mychasiuk&#39;s pediatric model11,12. In this study, SD rats were assigned to sham and mTBI groups. To demonstrate the reproducibility of this model, we conducted three independent replicates of this model along with the acute neurobehavioral assessment, with each experiment involving 8-12 rats. In this study, we used more than 30 mTBI rats, with...

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

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.

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

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