We thank Danye Jiang for editing the manuscript and insightful input. We thank Jhih Syuan Lin for assisting in manuscript preparation. This work was supported by the Ministry of Science and Technology of Taiwan (MOST 107-2320-B-002-063-MY2) to C.F.C.

All procedures described in this protocol were conducted under the approval of the Institutional Animal Care and Use Committee at Cheng Hsin General Hospital and National Taiwan University College of Medicine. Eight- to ten-week-old male C57BL/6 wild type mice were used in this protocol.
1. Anesthesia induction
<ol>
	<li>Anesthetize the mouse with ~4% isoflurane mixed with room air at ~0.2 L/min in an induction chamber connected to the isoflurane vaporizer.</li>
	<li>Ensure the respiratory pattern is smooth. Check the depth of anesthesia by confirming a lack of toe-pinch reflex in the animal.</li>
</ol>
2. Pre-surgical preparation
<ol>
	<li>Shave the mouse head with electrical clippers in a caudal to rostral direction. Do not trim the mouse whiskers. 
	NOTE: Loss of whiskers may influence the accuracy of subsequent behavioral test results.</li>
	<li>Place the mouse onto the stereotaxic frame. Carefully insert the ear bars into the ear canals. Ensure the mouse head is stabilized by both ear bars equally.</li>
	<li>Bring in the nose cone and maintain anesthesia at 1% - 2% isoflurane for the duration of the surgery.</li>
	<li>Apply ophthalmic ointment&#160;to both eyes to prevent drying out during the surgery. Keep the animal on a heating pad to maintain a body temperature of 37 &#730;C.</li>
	<li>Disinfect the shaved head with betadine followed by 70% alcohol using sterile cotton swabs. Repeat three times.</li>
</ol>
3. CCI surgery
<ol>
	<li>Administer 100 &#181;L of Bupivacaine (0.25%) subcutaneously using a 31 G insulin needle prior to the incision. Gently massage the injection site for better absorption. 
	NOTE: This local anesthetic provides pain relief directly at the site of surgery.</li>
	<li>Make a longitudinal incision (~1.5 cm) along the midline on the scalp with a scalpel or scissors. Use a hemostat to hold the skin off to the right side and allow the exposed skull to dry for 1 min. Use a sterile cotton swab to clean away any residual blood and tissues on the skull.</li>
	<li>Check that the mouse head is level in the horizontal plane.
	<ol>
		<li>Identify anatomical landmarks Bregma and Lambda and mark both locations with a sterile surgical marker/pencil.</li>
		<li>Ensure that the head of the animal is level in the rostral-caudal direction. Do this by measuring the Z coordinates of both Bregma and Lambda using a 31 G insulin needle attached to the stereotaxic frame. 
		NOTE: Adjust the ear bar vertically if necessary.</li>
		<li>Perform for the horizontal positioning of the animal head by following the same procedure of checking the Z coordinates at the midline along with two corresponding locations on the left and right side of the midline and adjust the ear bars if needed. 
		NOTE: A level and stable placement of the animal head is crucial for the reproducibility and reliability of the CCI model.</li>
	</ol>
	</li>
	<li>Use the same 31 G insulin needle to identify the craniectomy site. Set the XY origin to Bregma and laterally move the needle 3 mm to the right. Mark this position as the site of craniectomy and draw a circle 4 mm in diameter on the skull with a sterile surgical marker/pencil.</li>
	<li>Use a high-speed micro drill with a trephine (4 mm diameter) to cut along the pencil-outlined circle to create a 4 mm diameter open hole. Use a speed setting of 20,000 rpm. Avoid applying excess pressure. 
	NOTE: Perform this step quickly (usually within 30 s to 1 min) to prevent any thermal damage to the brain. Applying excess pressure while drilling may lead to accidental penetration that could compress and injure the brain surface.</li>
	<li>Carefully remove the bone flap with tweezer and temporally store it in ice cold normal saline. Gently rinse the hole with normal saline before applying pressure on the brain surface with the cotton swab tip to stop bleeding.</li>
	<li>Set the 2.5 mm diameter rounded impactor tip on the CCI device to an angle of 22.5&#730;. Zero the impact tip to the dural surface. Set the impact parameters on the control box to a velocity of 4 m/s and a deformation depth of 2 mm. Retract the metal tip. 
	NOTE: Zeroing the tip while it is statically and slightly pressed against the dural surface in the full stroke position improves the accuracy of the zero point and the reproducibility of the injury level.</li>
	<li>Discharge the piston to generate impaction on the brain. Place a sterile cotton swab onto the injured area to stop bleeding.</li>
	<li>Place the bone flap back to the mouse brain and secure with dental cement. Close the scalp with tissue adhesive (e.g., 3M Vetbond).</li>
</ol>
4. Postoperative recovery
<ol>
	<li>Place the mouse in a clean recovery cage with bedding under the heat lamp until full recovery.</li>
	<li>Provide moistened chow food and subcutaneously administer ketoprofen (5 mg/kg) for two consecutive days after surgery.</li>
	<li>Perform the above procedures except steps 3.7 and 3.8 for sham control animals.</li>
</ol>
5. Mouse euthanasia
<ol>
	<li>Euthanize mice on the day of study by isoflurane overdose and then decapitation. 
	NOTE: Several strategies can be used to euthanize the experimental animals prior to the sample collection.</li>
	<li>Collect brain samples for histological analysis.</li>
</ol>

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The authors have nothing to disclose.

The CCI protocol produces highly reproducible mechanical injury to the brain for cerebral contusion research. The following steps are crucial for generating consistent brain injury in animals using this CCI protocol.
First, the mouse head should be stably mounted on the stereotaxic frame and the anatomical landmarks Bregma and Lambda always in the same horizontal plane. Unsteady or unlevel head placement oftentimes result in varied injury levels between animals. To ensure the animal head is sa...

Cerebral contusion is a form of traumatic brain injury that ranks high among the deadliest health issues in modern society1. It is primarily caused by accidental events such as traffic accident that results in external forces applying mechanical energy to the head. Traumatic brain injury affects an approximate of 3.5 million people and accounts for 30% of all acute injury-related deaths in the US each year2. Patients who survive cerebral contusion oftentimes suffer from long-term consequences including focal motor weakness, sensory dysfunction, and mental illness1.
The primary injury of cerebral contusion is induced by mechanical factors including stretching and tearing forces, leading to immediate parenchymal structure deformation and focal CNS cell death3. Hemorrhage contusion is a general term for brain hemorrhages due to vascular tear at the site of head trauma4. Specifically, intraparenchymal hemorrhage occurs immediately after a cerebral contusion leading to delayed hematoma formation. Within the hematoma, hemoglobin and free iron released from the lysed red blood cells can further trigger blood-related toxicity5,6 which cause herniation, brain edema, and intracranial pressure elevation5,6. The collaborative functions of neurons (axons), glia, blood vessels, and supportive tissue are also compromised by the mass effect of hematoma7. Additionally, persistent and diffuse neuroinflammation with progressive neurodegeneration continue for months and cause secondary damage in the brain8.
Microglia activation is one of many important pathological features of cerebral contusion9,10. After sensing the damage-associated molecular patterns (DAMPs) and leaked blood in the injured tissue, activated microglia trigger neuroinflammation which furthers secondary brain damage11. In addition, chemoattractant released from microglia promotes peripheral immune cell infiltration into the traumatic territory resulting in production of reactive oxygen species and pro-inflammatory cytokines. This creates a self-perpetuating pro-inflammatory environment which triggers progressive brain injury9,12. Meanwhile, microglia with an alternatively activated phenotype can contribute to tissue homeostatic restoration and brain repair through clearing debris from the injured tissue13. Prevention of secondary neuroinflammation by reducing detrimental microglial immune responses has been shown to be particularly useful for promoting brain recovery from cerebral contusion3,9,10,12.
Several preclinical models have been developed for studying traumatic brain injury including weight-drop model, lateral fluid percussion injury, and blast wave model14,15. However, these models each have their weakness including high mortality rate during the procedure, low reproducibility of histological results, and high variability of inflicted injury between laboratories16,17. In comparison, the controlled cortical impact (CCI) model is more adequate for studying focal cerebral contusion because of its precise control and high reproducibility14,15,18,19.
Furthermore, through manipulating the biomechanical deformation parameters such as velocity and depth of impact, the severity of the induced damage can be controlled to produce a wide range of injury magnitudes, allowing researchers to mimic different levels of impairment oftentimes seen in patients17. The preclinical model of CCI was first developed in 189620. Since then, CCI has been the broadest applicable model to be modified for the use in primates21, swine22, sheep23, rats24, and mice25. Together these features make CCI one of the most suitable experimental cerebral contusion models26.
Our laboratory uses a commercially available pneumatic CCI impact system and tested biomechanical deformation parameters to produce moderately severe focal cerebral contusion that territorializes the primary sensory and motor cortical areas without damaging the hippocampus27,28. We and others demonstrated that this CCI procedure can be used to study clinical features of human cerebral contusion including brain tissue loss, neuronal injury, intraparenchymal hemorrhage, neuroinflammation, and sensorimotor deficiency24,25,27,28,29,30. Here, we detail a standard protocol to perform mouse CCI which allows one to ask questions regarding CCI-induced myelin loss, iron deposition, CNS inflammation, hemorrhagic toxicity and the responses of microglia/macrophages in the aftermath of focal cerebral contusion.

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			<td >cortical contusion injury impactor</td>
			<td >Custom Design &#38; Fabrication, Inc.</td>
			<td >S/N 49-2004-C, eCCI Model 6.3</td>
			<td >CCI device (S/N 49-2004-C, eCCI Model 6.3)</td>
		</tr>
		<tr >
			<td >cresyl violet acetate</td>
			<td >Sigma-Aldrich</td>
			<td >C5042</td>
			<td></td>
		</tr>
		<tr >
			<td >DAB staining kit</td>
			<td >Vector</td>
			<td >SK-4105</td>
			<td></td>
		</tr>
		<tr >
			<td >goat anti-rabbit IgG secondary antibody, Alexa Fluor 488</td>
			<td >Invitrogen</td>
			<td >A11034</td>
			<td></td>
		</tr>
		<tr >
			<td >goat anti-rat IgG secondary antibody, Alexa Fluor 594</td>
			<td >Invitrogen</td>
			<td >A11007</td>
			<td></td>
		</tr>
		<tr >
			<td >Mayer&#39;s Hematoxylin</td>
			<td >ScyTek</td>
			<td >HMM500</td>
			<td></td>
		</tr>
		<tr >
			<td >tweezers</td>
			<td >fine science tools</td>
			<td >11252-20 NO. 5</td>
			<td></td>
		</tr>
		<tr >
			<td >isoflurane</td>
			<td >Panion &#38; BF Biotech Inc.</td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >Bupivacaine 0.25%</td>
			<td >Hospira</td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >lithium carbonate</td>
			<td >Sigma-Aldrich</td>
			<td >62470</td>
			<td></td>
		</tr>
		<tr >
			<td >steriotexic frame</td>
			<td >stoelting</td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >scissors</td>
			<td >fine science tools</td>
			<td >14068-12</td>
			<td></td>
		</tr>
		<tr >
			<td >solvent blue 38</td>
			<td >Sigma-Aldrich</td>
			<td >S3382</td>
			<td></td>
		</tr>
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</table>

a preclinical controlled cortical impact model for traumatic hemorrhage contusion and neuroinflammation

Cerebral contusion is a severe medical problem affecting millions of people worldwide each year. There is an urgent need to understand the pathophysiological mechanism and to develop effective therapeutic strategy for this devastating neurological disorder. Intraparenchymal hemorrhage and post-traumatic inflammatory response induced by initial physical impact can aggravate microglia/macrophage activation and neuroinflammation which subsequently worsen brain pathology. We provide here a controlled cortical impact (CCI) protocol that can reproduce experimental cortical contusion in mice by using a pneumatic impactor system to deliver mechanical force with controllable magnitude and velocity onto the dural surface. This preclinical model allows researchers to induce moderately severe focal cerebral contusion in mice and to investigate a wide range of post-traumatic pathological progressions including hemorrhage contusion, microglia/macrophage activation, iron toxicity, axonal injury, as well as short-term and long-term neurobehavioral deficits. The present protocol can be useful for exploring the long-term effects of and potential interventions for cerebral contusion.

Illustration of stereotactic placement and craniotomy procedure.
The CCI model is known for its stability and reproducibility in producing injury ranging from mild to severe18. Proper stereotactic technique and craniotomy procedure are major determinants in producing stable and reproducible CCI-induced brain injury (Figure 1A,B). An ideal craniotomy procedure would cause minimal histological injury in the s...

Watch this Scientific Journal Video about A Preclinical Controlled Cortical Impact Model for Traumatic Hemorrhage Contusion and Neuroinflammation at JoVE.com

A Preclinical Controlled Cortical Impact Model for Traumatic Hemorrhage Contusion and Neuroinflammation

Intraparenchymal hemorrhage and neuroinflammation accompanied by cerebral contusion can trigger severe secondary brain injury. This protocol details a mouse controlled cortical impact (CCI) model allowing researchers to study hemorrhage contusion and post-traumatic immune responses and explore potential therapeutics.

Cerebral contusion is a severe medical problem affecting millions of people worldwide each year. There is an urgent need to understand the ...

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1.7K Views.  Cheng Hsin General Hospital. Intraparenchymal hemorrhage and neuroinflammation accompanied by cerebral contusion can trigger severe secondary brain injury. This protocol details a mouse controlled cortical impact (CCI) model allowing researchers to study hemorrhage contusion and post-traumatic immune responses and explore potential therapeutics.

Video: A Preclinical Controlled Cortical Impact Model for Traumatic Hemorrhage Contusion and Neuroinflammation

Gene Transfer for Ischemic Heart Failure in a Preclinical Model

Various emerging technologies are being developed for patients with heart failure. Well-established preclinical evaluations are necessary to determine their efficacy and safety.
Gene therapy using viral vectors is one of the most promising approaches for treating cardiac diseases. Viral delivery of various different genes by changing the carrier gene has immeasurable therapeutic potential.
In this video, the full process of an animal model of heart failure creation followed by gene transfer is presented using a swine model. First, myocardial infarction is created by occluding the proximal left anterior descending coronary artery. Heart remodeling results in chronic heart failure. Unique to our model is a fairly large scar which truly reflects patients with severe heart failure who require aggressive therapy for positive outcomes. After myocardial infarct creation and development of scar tissue, an intracoronary injection of virus is demonstrated with simultaneous nitroglycerine infusion. Our injection method provides simple and efficient gene transfer with enhanced gene expression. This combination of a myocardial infarct swine model with intracoronary virus delivery has proven to be a consistent and reproducible methodology, which helps not only to test the effect of individual gene, but also compare the efficacy of many genes as therapeutic candidates.

A method of gene transfer for the treatment of ischemic heart failure is described using a swine model of myocardial infarction. Our simple and reproducible method enables us to readily evaluate the efficacy of various gene transfers with a very simple and reproducible way.

Various emerging technologies are being developed for patients with heart failure. Well-established preclinical evaluations are necessary to determine ...

Biomarkers in an Animal Model for Revealing Neural, Hematologic, and Behavioral Correlates of PTSD

Identification of biomarkers representing the evolution of the pathophysiology of Post Traumatic Stress Disorder (PTSD) is vitally important, not only for objective diagnosis but also for the evaluation of therapeutic efficacy and resilience to trauma. Ongoing research is directed at identifying molecular biomarkers for PTSD, including traumatic stress induced proteins, transcriptomes, genomic variances and genetic modulators, using biologic samples from subjects' blood, saliva, urine, and postmortem brain tissues. However, the correlation of these biomarker molecules in peripheral or postmortem samples to altered brain functions associated with psychiatric symptoms in PTSD remains unresolved. Here, we present an animal model of PTSD in which both peripheral blood and central brain biomarkers, as well as behavioral phenotype, can be collected and measured, thus providing the needed correlation of the central biomarkers of PTSD, which are mechanistic and pathognomonic but cannot be collected from people, with the peripheral biomarkers and behavioral phenotypes, which can.
Our animal model of PTSD employs restraint and tail shocks repeated for three continuous days - the inescapable tail-shock model (ITS) in rats. This ITS model mimics the pathophysiology of PTSD 17, 7, 4, 10. We and others have verified that the ITS model induces behavioral and neurobiological alterations similar to those found in PTSD subjects 17, 7, 10, 9. Specifically, these stressed rats exhibit (1) a delayed and exaggerated startle response appearing several days after stressor cessation, which given the compressed time scale of the rat's life compared to a humans, corresponds to the one to three months delay of symptoms in PTSD patients (DSM-IV-TR PTSD Criterian D/E 13), (2) enhanced plasma corticosterone (CORT) for several days, indicating compromise of the hypothalamopituitary axis (HPA), and (3) retarded body weight gain after stressor cessation, indicating dysfunction of metabolic regulation.
The experimental paradigms employed for this model are: (1) a learned helplessness paradigm in the rat assayed by measurement of acoustic startle response (ASR) and a charting of body mass; (2) microdissection of the rat brain into regions and nuclei; (3) enzyme-linked immunosorbent assay (ELISA) for blood levels of CORT; (4) a gene expression microarray plus related bioinformatics tools 18. This microarray, dubbed rMNChip, focuses on mitochondrial and mitochondria-related nuclear genes in the rat so as to specifically address the neuronal bioenergetics hypothesized to be involved in PTSD.

We describe a rat model of post traumatic stress disorder (PTSD) that reveals the persistent alterations in neuroendocrine function and the delayed long-term, exaggerated fear response, characteristic of PTSD patients. The animal model and methods described here are useful for correlating biomarkers in brain nuclei, which are mechanistic but cannot be measured in patients, with biomarkers in peripheral white blood cells, which can.

Identification of biomarkers representing the evolution of the pathophysiology of Post Traumatic Stress Disorder (PTSD) is vitally important, not only for ...

A Contusion Model of Severe Spinal Cord Injury in Rats

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is described to obtain a consistent model of severe SCI. Use of a stereotactic frame and computer controlled impactor allows for creation of reproducible injury. Hypothermia and urinary tract infection pose significant challenges in the post-operative period. Careful monitoring of animals with daily weight recording and bladder expression allows for early detection of post-operative complications. The functional results of this contusion model are equivalent to transection models. The contusion model can be utilized to evaluate the efficacy of both neuroprotective and neuroregenerative approaches.

A contusion model of severe spinal cord injury is described. Detailed pre-operative, operative and post-operative steps are described to obtain a consistent model.

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is ...

A Murine Model of Subarachnoid Hemorrhage

In this video publication a standardized mouse model of subarachnoid hemorrhage (SAH) is presented. Bleeding is induced by endovascular Circle of Willis perforation (CWp) and proven by intracranial pressure (ICP) monitoring. Thereby a homogenous blood distribution in subarachnoid spaces surrounding the arterial circulation and cerebellar fissures is achieved. Animal physiology is maintained by intubation, mechanical ventilation, and continuous on-line monitoring of various physiological and cardiovascular parameters: body temperature, systemic blood pressure, heart rate, and hemoglobin saturation. Thereby the cerebral perfusion pressure can be tightly monitored resulting in a less variable volume of extravasated blood. This allows a better standardization of endovascular filament perforation in mice and makes the whole model highly reproducible. Thus it is readily available for pharmacological and pathophysiological studies in wild type and genetically altered mice.

A standardized mouse model of subarachnoid hemorrhage by intraluminal Circle of Willis perforation is described. Vessel perforation and subarachnoid bleeding are monitored by intracranial pressure monitoring. In addition various vital parameters are recorded and controlled to maintain physiologic conditions.

In this video publication a standardized mouse model of subarachnoid  hemorrhage (SAH) is presented. Bleeding is induced by endovascular Circle of  Willis ...

A Preclinical Murine Model of Hepatic Metastases

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, murine pancreatic tumor model of hepatic metastases via a hemispleen injection of syngeneic murine pancreatic tumor cells is described. This model mimics many of the clinical conditions in patients with metastatic disease to the liver. Mice consistently develop metastases in the liver allowing for investigation of the metastatic process, experimental therapy testing, and tumor immunology research.

A preclinical, murine model of hepatic metastases performed via a hemispleen injection technique.

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, ...

Controlled Cortical Impact Model for Traumatic Brain Injury

Every year over a million Americans suffer a traumatic brain injury (TBI). Combined with the incidence of TBIs worldwide, the physical, emotional, social, and economical effects are staggering. Therefore, further research into the effects of TBI and effective treatments is necessary. The controlled cortical impact (CCI) model induces traumatic brain injuries ranging from mild to severe. This method uses a rigid impactor to deliver mechanical energy to an intact dura exposed following a craniectomy. Impact is made under precise parameters at a set velocity to achieve a pre-determined deformation depth. Although other TBI models, such as weight drop and fluid percussion, exist, CCI is more accurate, easier to control, and most importantly, produces traumatic brain injuries similar to those seen in humans. However, no TBI model is currently able to reproduce pathological changes identical to those seen in human patients. The CCI model allows investigation into the short-term and long-term effects of TBI, such as neuronal death, memory deficits, and cerebral edema, as well as potential therapeutic treatments for TBI.

Traumatic brain injuries (TBIs) remain a serious health problem. Using the controlled cortical impact surgery model, research on the effects of TBI and possible treatment methods may be performed.

Every year over a million Americans suffer a traumatic brain injury (TBI).  Combined with the incidence of TBIs worldwide, the physical, emotional, ...

A Novel Model of Mild Traumatic Brain Injury for Juvenile Rats

Despite growing evidence that childhood represents a major risk period for mild traumatic brain injury (mTBI) from sports-related concussions, motor vehicle accidents, and falls, a reliable animal model of mTBI had previously not been developed for this important aspect of development. The modified weight-drop technique employs a glancing impact to the head of a freely moving rodent transmitting acceleration, deceleration, and rotational forces upon the brain. When applied to juvenile rats, this modified weight-drop technique induced clinically relevant behavioural outcomes that were representative of post-concussion symptomology. The technique is a rapidly applied procedure with an extremely low mortality rate, rendering it ideal for high-throughput studies of therapeutics. In addition, because the procedure involves a mild injury to a closed head, it can easily be used for studies of repetitive brain injury. Owing to the simplistic nature of this technique, and the clinically relevant biomechanics of the injury pathophysiology, the modified weight-drop technique provides researchers with a reliable model of mTBI that can be used in a wide variety of behavioural, molecular, and genetic studies.

The modified weight-drop technique is an easy, cost-effective procedure used for the induction of mild traumatic brain injury in juvenile rats. This novel technique produces clinically relevant symptomology that will advance the study of mild traumatic brain injury (mTBI) and concussion.

Despite growing evidence that childhood represents a major risk period for mild traumatic brain injury (mTBI) from sports-related concussions, motor ...

Integrated Compensatory Responses in a Human Model of Hemorrhage

Hemorrhage is the leading cause of trauma-related deaths, partly because early diagnosis of the severity of blood loss is difficult. Assessment of hemorrhaging patients is difficult because current clinical tools provide measures of vital signs that remain stable during the early stages of bleeding due to compensatory mechanisms. Consequently, there is a need to understand and measure the total integration of mechanisms that compensate for reduced circulating blood volume and how they change during ongoing progressive hemorrhage. The body&#39;s reserve to compensate for reduced circulating blood volume is called the &#39;compensatory reserve&#39;. The compensatory reserve can be accurately evaluated with real-time measurements of changes in the features of the arterial waveform measured with the use of a high-powered computer. Lower Body Negative Pressure (LBNP) has been shown to simulate many of the physiological responses in humans associated with hemorrhage, and is used to study the compensatory response to hemorrhage. The purpose of this study is to demonstrate how compensatory reserve is assessed during progressive reductions in central blood volume with LBNP as a simulation of hemorrhage.

The purpose of this protocol is to demonstrate the techniques for measuring compensatory responses to reduced central blood volume using lower body negative pressure as a noninvasive experimental model of human hemorrhage which can be used to quantify the total integration of compensatory mechanisms to blood volume deficit in humans.

Hemorrhage is the leading cause of trauma-related deaths, partly because early diagnosis of the severity of blood loss is difficult. Assessment of ...

A Mouse Model of Single and Repetitive Mild Traumatic Brain Injury

Mild Traumatic Brain Injury (mTBI) can result in the acute loss of brain function, including a period of confusion, a loss of consciousness (LOC), focal neurological deficits and even amnesia. Athletes participating in contact sports are at high risk of exposure to large number of mTBIs. In terms of the level of injury in a sporting athlete, a mTBI is defined as a mild injury that does not cause gross pathological changes, but does cause short-term neurological deficits that are spontaneously resolved. Despite previous attempts to model mTBI in mice and rats, many have reported gross adverse effects including skull fractures, intracerebral bleeding, axonal injury and neuronal cell death. Herein, we describe our highly reproducible animal model of mTBI that reproduces clinically relevant symptoms. This model uses a custom made pneumatic impactor device to deliver a closed-head trauma. This impact is made under precise velocity and deformation parameters, creating a reliable and reproducible model to examine the mechanisms that contribute to effects of single or repetitive concussive mTBI.

Athletes absorb several hundred mild traumatic brain injuries (mTBI)/concussions every year; however, the consequence of these on the brain is poorly understood. Therefore, an animal model of single and repetitive mTBI that consistently replicates clinically relevant symptoms provides the means to advance the study of mTBI and concussion.

Mild Traumatic Brain Injury (mTBI) can result in the acute loss of brain function, including a period of confusion, a loss of consciousness (LOC), focal ...

PET Imaging of Neuroinflammation Using [11C]DPA-713 in a Mouse Model of Ischemic Stroke

Neuroinflammation is central to the pathological cascade following ischemic stroke. Non-invasive molecular imaging methods have the potential to provide critical insights into the temporal dynamics and role of certain neuroimmune interactions in stroke. Specifically, Positron Emission Tomography (PET) imaging of translocator protein 18 kDa (TSPO), a marker of activated microglia and peripheral myeloid-lineage cells, provides a means to detect and track neuroinflammation in vivo. Here, we present a method to accurately quantify neuroinflammation using [11C]N,N-Diethyl-2-[2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl]acetamide ([11C]DPA-713), a promising second generation TSPO-PET radiotracer, in distal middle cerebral artery occlusion (dMCAO) compared to sham-operated mice. MRI was performed 2 days post-dMCAO surgery to confirm stroke and define the infarct location and volume. PET/Computed Tomography (CT) imaging was carried out 6 days post-dMCAO to capture the peak increase in TSPO levels following stroke. Quantitation of PET images was conducted to assess the uptake of [11C]DPA-713 in the brain and spleen of dMCAO and sham mice to assess central and peripheral levels of inflammation. In vivo [11C]DPA-713 brain uptake was confirmed using ex vivo autoradiography.

PET Imaging of Neuroinflammation Using [11C]DPA-713 in a Mouse Model of Ischemic Stroke

Positron Emission Tomography (PET) imaging of translocator protein 18 kDa (TSPO) provides a non-invasive means to visualize the dynamic role of neuroinflammation in the development and progression of brain diseases. This protocol describes TSPO-PET and ex vivo autoradiography to detect neuroinflammation in a mouse model of ischemic stroke.

Neuroinflammation is central to the pathological cascade following ischemic stroke. Non-invasive molecular imaging methods have the potential to provide ...