The authors have no acknowledgements.

This protocol was approved by the Institutional Animal Care and Use Committee of Seoul National University Bundang Hospital. Animal care and experiments were conducted according to the United States National Institutes of Health Guide for the Care and Use of Laboratory Animals.
1. Surgical Preparation
<ol>
	<li>Prior to surgery, flush the catheters with sterile saline to ensure patency.</li>
	<li>Put a heating blanket on the operating table, and cover the table with a sterile drape.</li>
	<l...

<ol>
	<li>Greenberg, R. 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=Contemporary+analysis+of+descending+thoracic+and+thoracoabdominal+aneurysm+repair:+a+comparison+of+endovascular+and+open+techniques.">Contemporary analysis of descending thoracic and thoracoabdominal aneurysm repair: a comparison of endovascular and open techniques.</a> Circulation. 118 (8), 808-817 (2008).</li><li>Okita, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fighting+spinal+cord+complication+during+surgery+for+thoracoabdominal+aortic+disease.">Fighting spinal cord complication during surgery for thoracoabdominal aortic disease.</a> Gen Thorac Cardiovasc Surg. 59 (2), 79-90 (2011).</li><li>Fleck, T. M., 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=Improved+outcome+in+thoracoabdominal+aortic+aneurysm+repair:+the+role+of+cerebrospinal+fluid+drainage.">Improved outcome in thoracoabdominal aortic aneurysm repair: the role of cerebrospinal fluid drainage.</a> Neurocrit Care. 2 (1), 11-16 (2005).</li><li>Kouchoukos, N. T., 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=Hypothermic+bypass+and+circulatory+arrest+for+operations+on+the+descending+thoracic+and+thoracoabdominal+aorta.">Hypothermic bypass and circulatory arrest for operations on the descending thoracic and thoracoabdominal aorta.</a> Ann Thorac Surg. 60 (1), 67-76 (1995).</li><li>Taira, Y., Marsala, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+proximal+arterial+perfusion+pressure+on+function,+spinal+cord+blood+flow,+and+histopathologic+changes+after+increasing+intervals+of+aortic+occlusion+in+the+rat.">Effect of proximal arterial perfusion pressure on function, spinal cord blood flow, and histopathologic changes after increasing intervals of aortic occlusion in the rat.</a> Stroke. 27 (10), 1850-1858 (1996).</li><li>Tveten, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+vascularity.+III.+The+spinal+cord+arteries+in+man.">Spinal cord vascularity. III. The spinal cord arteries in man.</a> Acta Radiol Diagn (Stockh). 17 (3), 257-273 (1976).</li><li>Woollam, D. H., Millen, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+arterial+supply+of+the+spinal+cord+and+its+significance.">The arterial supply of the spinal cord and its significance.</a> J Neurol Neurosurg Psychiatry. 18 (2), 97-102 (1955).</li><li>Kennedy, H. S., Puth, F., Van Hoy, M., Le Pichon, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+removing+the+brain+and+spinal+cord+as+one+unit+from+adult+mice+and+rats.">A method for removing the brain and spinal cord as one unit from adult mice and rats.</a> Lab Anim (NY). 40 (2), 53-57 (2011).</li><li>Umehara, S., Goyagi, T., Nishikawa, T., Tobe, Y., Masaki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Esmolol+and+landiolol,+selective+&#946;1+adrenoreceptor+antagonists,+provide+neuroprotection+against+spinal+cord+ischemia+and+reperfusion+in+rats.">Esmolol and landiolol, selective &#946;1 adrenoreceptor antagonists, provide neuroprotection against spinal cord ischemia and reperfusion in rats.</a> Anesth Analg. 110 (4), 1133-1137 (2010).</li><li>De Ley, G., Nshimyumuremyi, J. B., Leusen, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemispheric+blood+flow+in+the+rat+after+unilateral+common+carotid+occlusion:+evolution+with+time.">Hemispheric blood flow in the rat after unilateral common carotid occlusion: evolution with time.</a> Stroke. 16 (1), 69-73 (1985).</li><li>Coyle, P., Panzenbeck, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collateral+development+after+carotid+artery+occlusion+in+Fischer+344+rats.">Collateral development after carotid artery occlusion in Fischer 344 rats.</a> Stroke. 21 (2), 316-321 (1990).</li><li>Levine, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anoxic-ischemic+encephalopathy+in+rats.">Anoxic-ischemic encephalopathy in rats.</a> Am J Pathol. 36, 1-17 (1960).</li><li>Prior, B. M., 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=Time+course+of+changes+in+collateral+blood+flow+and+isolated+vessel+size+and+gene+expression+after+femoral+artery+occlusion+in+rats.">Time course of changes in collateral blood flow and isolated vessel size and gene expression after femoral artery occlusion in rats.</a> Am J Physiol Heart Circ Physiol. 287 (6), H2434-H2447 (2004).</li><li>Yang, H. T., Feng, Y., Allen, L. A., Protter, A., Terjung, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+and+specificity+of+bFGFincreased+collateral+flow+in+experimental+peripheral+arterial+insufficiency.">Efficacy and specificity of bFGFincreased collateral flow in experimental peripheral arterial insufficiency.</a> Am J Physiol Heart Circ Physiol. 278 (6), H1966-H1973 (2000).</li><li>Kakinohana, M., Fuchigami, T., Nakamura, S., Sasara, T., Kawabata, T., Sugahara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrathecal+administration+of+morphine,+but+not+small+dose,+induced+spastic+paraparesis+after+a+noninjurious+interval+of+aortic+occlusion+in+rats.">Intrathecal administration of morphine, but not small dose, induced spastic paraparesis after a noninjurious interval of aortic occlusion in rats.</a> Anesth Analg. 96 (3), 769-775 (2003).</li><li>Horiuchi, T., 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+effects+of+the+delta-opioid+agonist+SNC80+on+hind-limb+motor+function+and+neuronal+injury+after+spinal+cord+ischemia+in+rats.">The effects of the delta-opioid agonist SNC80 on hind-limb motor function and neuronal injury after spinal cord ischemia in rats.</a> Anesth Analg. 99 (1), 235-240 (2004).</li><li>Griepp, R. B., Griepp, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+perfusion+and+protection+during+descending+thoracic+and+thoracoabdominal+aortic+surgery:+the+collateral+network+concept.">Spinal cord perfusion and protection during descending thoracic and thoracoabdominal aortic surgery: the collateral network concept.</a> Ann Thorac Surg. 83 (2), S865-S869 (2007).</li></ol>

In the current study, we demonstrated a rat model of spinal cord ischemia based on Taira and Marsala&#39;s method5 that induces variable degrees of motor deficit in the hind limb depending on the aortic occlusion time.
The length of aortic occlusion can affect the degree of motor deficit. If the aortic occlusion time is longer, the motor deficit becomes more severe. Thus, researchers can achieve a certain degree of motor deficit by controlling the aortic occlusion time ...

Paraplegia is a fatal complication of thoracoabdominal aortic aneurysm surgery. It results from spinal cord ischemia-reperfusion injury that occurs during cross-clamping and unclamping of the aorta.1 Several strategies including systemic hypothermia and cerebrospinal drainage have been introduced to protect the spinal cord,2,3,4 but many patients remain affected by the injury.
Several animal spinal cord ischemia models have been introduced to investigate its pathogenesis and devise protective strategies against the injury. In the current study, we outline a rat model of spinal cord ischemia based on Taira and Marsala&#39;s method.5 The spinal circulation system in rats is very similar to the spinal cord vascular and collateral system in humans, although there are some differences in the size and location.6,7 Thus, a rat is an anatomically suitable animal to utilize for an experimental model investigating the pathogenesis, complications, and treatment of spinal cord ischemia. Moreover, this spinal cord ischemia model produces reliable aortic occlusion with minimal intervention by utilizing an intravascular balloon occlusion of the thoracic aorta.
In this study, we demonstrated that this rat model of spinal cord ischemia induces reproducible motor deficits in the hind limbs that vary in severity depending on the aortic occlusion time.

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reproducible motor deficit following aortic occlusion in a rat model of spinal cord ischemia

Spinal cord ischemia is a fatal complication following thoracoabdominal aortic aneurysm surgery. Researchers can investigate the strategies for preventing and treating this complication using experimental models of spinal cord ischemia. The model described here demonstrates varying degrees of paraplegia that relate to the length of occlusion following thoracic aortic occlusion in a rat spinal cord ischemia model.
A 2-Fr. balloon-tipped catheter was advanced through the femoral artery into the descending thoracic aorta until the catheter tip was placed at the left subclavian artery in anesthetized male Sprague-Dawley rats. Spinal cord ischemia was induced by inflating the catheter balloon. After a set period of occlusion (9, 10, or 11 min), the balloon was deflated. Neurologic assessment was performed using the motor deficit index at 24 h after surgery, and the spinal cord was harvested for histopathological examination.
Rats that underwent 9 min of aortic occlusion showed mild and reversible motor impairment in the hind limb. Rats subjected to 10 min of aortic occlusion presented with moderate but reversible motor impairment. Rats subjected to 11 min of aortic occlusion displayed complete and persistent paralysis. The motor neurons in the spinal cord sections were more preserved in rats subjected to shorter duration of aortic occlusion.
Researchers can achieve a reproducible hind limb motor deficit following thoracic aortic occlusion using this spinal cord ischemia model.

During a period of spinal cord ischemia, aortic occlusion was performed for 9 min (n=3), 10 min (n=3), or 11 min (n=3). The motor deficit index in rats is presented in Table 2. Rats that underwent 9 min of aortic occlusion showed a mild and reversible motor impairment in the hind-limb. Rats subjected to 10 min of aortic occlusion presented with moderate motor deficit, but not complete paralysis. Rats that underwent 11 min of occlusion time displayed complete and persistent paralysis.
Represent...

Watch this Scientific Journal Video about Reproducible Motor Deficit Following Aortic Occlusion in a Rat Model Of Spinal Cord Ischemia at JoVE.com

Reproducible Motor Deficit Following Aortic Occlusion in a Rat Model Of Spinal Cord Ischemia

This study demonstrates the technique to make a minimally invasive and easily reproducible model of spinal cord ischemia in rats. Various degrees of hind limb motor deficit can be produced by controlling the aortic occlusion time.

Spinal cord ischemia is a fatal complication following thoracoabdominal aortic aneurysm surgery. Researchers can investigate the strategies for preventing ...

The overall goal of this procedure is to present the technique to make a spinal cord ischemia model in a rat. Demonstrating the procedure will be done by Mi-Sun Lim. The catheter placed in tail artery is used for monitoring of arterial pressure.After completing the catheterization, advance the Fogarty catheter through the femoral artery into the descending thoracic aorta. To induce spinal cord ischemia, inflate the Fogarty catheter and drain the blood flow from the carotid artery into the external blood reservoir for controlling proximal arterial pressure. After the scheduled occlusion time, deflate the Fogarty catheter balloon, reinfuse the drained blood and remove the femur catheter.Once the rat is anesthetized, place the rat in the operating table in the ventral position and maintain anesthesia with spontaneous respiration using a facial mask of inhaled isoflurane Make a horizontal skin incision on the right inguinal area. Using a 4.0 black silk suture, place a loose tie on both proximal and distal ends of the artery to maximize the exposure. While monitoring the arterial pressure through the tail artery, remove the catheters from the femoral and carotid arteries and close the wound with silk sutures.Hind-limb motor function can be assessed using the motor deficit index. The motor deficit index is defined as the sum of the scores in relation with the lower extremities plus placing/stepping reflex and the maximum deficit is indicated by a score of six. At the assessment of hind-limb motor function at 24 hour after surgery, rats that underwent nine minutes of aortic occlusion showed mild and reversible motor impairment in the hind-limb.Rats subjected to 10 minutes of aortic occlusion presented moderate motor deficit, but not complete paralysis. Rats that underwent 11 minutes of occlusion time, displayed complete and persistent paralysis. You can induce various degrees of hind-limb motor deficit by controlling the aortic occlusion time using this spinal cord ischemia model.Once mastered, this technique can be performed within 40 minutes. Thank you for watching and good luck with your experiment.

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7.1K ビュー.  SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul. The overall goal of this procedure is to present the technique to make a spinal cord ischemia model in a rat. Demonstrating the procedure will be done by Mi-Sun Lim. The catheter placed in tail artery is used for monitoring of arterial pressure.After completing the catheterization, advance the Fogarty catheter through the femoral artery into the descending thoracic aorta. To induce spinal cord ischemia, inflate the Fogarty catheter and drain the blood flow from the carotid artery into ...

ビデオ: Reproducible Motor Deficit Following Aortic Occlusion in a Rat Model Of Spinal Cord Ischemia

Acute and Chronic Tactile Sensory Testing after Spinal Cord Injury in Rats

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory testing in rat SCI models is needed. However, until recently, no single testing approach had been validated for SCI so that standardized methods have not been implemented across labs. Additionally, available testing methods could not be implemented acutely or when severe motor impairments existed, preventing studies of the development of SCI-induced allodynia3. Here we present two validated sensory testing methods using von Frey Hair (VFH) monofilaments which quantify changes in tactile sensory thresholds after SCI4-5. One test is the well-established Up-Down test which demonstrates high sensitivity and specificity across different SCI severities when tested chronically5. The other test is a newly-developed dorsal VFH test that can be applied acutely after SCI when allodynia develops, prior to motor recovery4-5. Each VFH monofilament applies a calibrated force when touched to the skin of the hind paw until it bends. In the up-down method, alternating VFHs of higher or lower forces are used on the plantar L5 dermatome to delineate flexor withdrawal thresholds. Successively higher forces are applied until withdrawal occurs then lower force VFHs are used until withdrawal ceases. The tactile threshold reflects the force required to elicit withdrawal in 50% of the stimuli. For the new test, each VFH is applied to the dorsal L5 dermatome of the paw while the rat is supported by the examiner. The VFH stimulation occurs in ascending order of force until at least 2 of 3 applications at a given force produces paw withdrawal. Tactile sensory threshold is the lowest force to elicit withdrawal 66% of the time. Acclimation, testing and scoring procedures are described. Aberrant trials that require a retest and typical trials are defined. Animal use was approved by Ohio State University Animal Care and Use Committee.

We describe two tactile sensory testing methods for acute or chronic periods of spinal cord injury in rats. These validated procedures can detect the development and maintenance of allodynia-like sensations.

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory ...

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 ...

2-Vessel Occlusion/Hypotension: A Rat Model of Global Brain Ischemia

Cardiac arrest followed by resuscitation often results in dramatic brain damage caused by ischemia and subsequent reperfusion of the brain. Global brain ischemia produces damage to specific brain regions shown to be highly sensitive to ischemia 1. Hippocampal neurons have higher sensitivity to ischemic insults compared to other cell populations, and specifically, the CA1 region of the hippocampus is particularly vulnerable to ischemia/reperfusion 2.
The design of therapeutic interventions, or study of mechanisms involved in cerebral damage, requires a model that produces damage similar to the clinical condition and in a reproducible manner. Bilateral carotid vessel occlusion with hypotension (2VOH) is a model that produces reversible forebrain ischemia, emulating the cerebral events that can occur during cardiac arrest and resuscitation. We describe a model modified from Smith et al. (1984) 2, as first presented in its current form in Sanderson, et al. (2008) 3, which produces reproducible injury to selectively vulnerable brain regions 3-6. The reliability of this model is dictated by precise control of systemic blood pressure during applied hypotension, the duration of ischemia, close temperature control, a specific anesthesia regimen, and diligent post-operative care. An 8-minute ischemic insult produces cell death of CA1 hippocampal neurons that progresses over the course of 6 to 24 hr of reperfusion, while less vulnerable brain regions are spared. This progressive cell death is easily quantified after 7-14 days of reperfusion, as a near complete loss of CA1 neurons is evident at this time.
In addition to this brain injury model, we present a method for CA1 damage quantification using a simple, yet thorough, methodology. Importantly, quantification can be accomplished using a simple camera-mounted microscope, and a free ImageJ (NIH) software plugin, obviating the need for cost-prohibitive stereology software programs and a motorized microscopic stage for damage assessment.

Bilateral carotid occlusion coupled with systemic hypotension produces global brain ischemia in the rat, resulting in damage to the hippocampus with reproducible severity. Animal subjects are impaired with predictable patterns of brain damage, they recover expediently, and mortality rates are comparatively low.

Cardiac arrest followed by resuscitation often results in dramatic brain damage caused by ischemia and subsequent reperfusion of the brain. Global brain ...

Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury

During breathing, activation of respiratory muscles is coordinated by integrated input from the brain, brainstem, and spinal cord. When this coordination is disrupted by spinal cord injury (SCI), control of respiratory muscles innervated below the injury level is compromised1,2 leading to respiratory muscle dysfunction and pulmonary complications. These conditions are among the leading causes of death in patients with SCI3. Standard pulmonary function tests that assess respiratory motor function include spirometrical and maximum airway pressure outcomes: Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Maximal Inspiratory Pressure (PImax) and Maximal Expiratory Pressure (PEmax)4,5. These values provide indirect measurements of respiratory muscle performance6. In clinical practice and research, a surface electromyography (sEMG) recorded from respiratory muscles can be used to assess respiratory motor function and help to diagnose neuromuscular pathology. However, variability in the sEMG amplitude inhibits efforts to develop objective and direct measures of respiratory motor function6. Based on a multi-muscle sEMG approach to characterize motor control of limb muscles7, known as the voluntary response index (VRI)8, we developed an analytical tool to characterize respiratory motor control directly from sEMG data recorded from multiple respiratory muscles during the voluntary respiratory tasks. We have termed this the Respiratory Motor Control Assessment (RMCA)9. This vector analysis method quantifies the amount and distribution of activity across muscles and presents it in the form of an index that relates the degree to which sEMG output within a test-subject resembles that from a group of healthy (non-injured) controls. The resulting index value has been shown to have high face validity, sensitivity and specificity9-11. We showed previously9 that the RMCA outcomes significantly correlate with levels of SCI and pulmonary function measures. We are presenting here the method to quantitatively compare post-spinal cord injury respiratory multi-muscle activation patterns to those of healthy individuals.

Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment RMCA in Individuals with Chronic Spinal Cord Injury

The purpose of this publication is to present our original work on a multi-muscle surface electromyographic approach to quantitatively characterize respiratory muscle activation patterns in individuals with chronic spinal cord injury using vector-based analysis.

During breathing, activation of respiratory muscles is coordinated by integrated input from the brain, brainstem, and spinal cord. When this coordination ...

Reproducable Paraplegia by Thoracic Aortic Occlusion in a Murine Model of Spinal Cord Ischemia-reperfusion

Background 
Lower extremity paralysis continues to complicate aortic interventions. The lack of understanding of the underlying pathology has hindered advancements to decrease the occurrence this injury.&#160;The current model demonstrates reproducible lower&#160;extremity paralysis following thoracic aortic occlusion.
Methods 
Adult male C57BL6 mice were anesthetized with isoflurane. Through a cervicosternal incision the aorta was exposed. The descending thoracic aorta and left subclavian arteries were identified without entrance into pleural space. Skeletonization of these arteries was followed by immediate closure (Sham) or occlusion for 4 min (moderate ischemia) or 8 min (prolonged ischemia). The sternotomy and skin were closed and the mouse was transferred to warming bed for recovery.&#160; Following recovery, functional analysis was obtained at 12 hr intervals until 48 hr.
Results 
Mice that underwent sham surgery showed no observable hind&#160;limb deficit. Mice subjected to moderate ischemia for 4 min had minimal functional deficit at 12 hr followed by progression to complete paralysis at 48 hr. Mice subjected to prolonged ischemia had an immediate paralysis with no observable hind-limb movement at any point in the postoperative period. There was no observed intraoperative or post&#160;operative mortality.
Conclusion 
Reproducible lower extremity paralysis whether immediate or delayed can be achieved in a murine model. Additionally, by using a median sternotomy and careful dissection, high survival rates, and reproducibility can be achieved.

The lack of mechanistic understanding of spinal cord ischemia-reperfusion injury has hindered further adjuncts to prevent paraplegia following high risk aortic operations. Thus, the development of animal models is imperative. This manuscript demonstrates reproducible lower extremity paralysis following thoracic aortic occlusion in a murine model.

Background
Lower extremity paralysis continues to complicate aortic interventions. The lack of understanding of the underlying pathology has hindered ...

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 Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter connected to a radio transmitter into the femoral artery of rats that underwent a T4 spinal cord transection with or without grafting of embryonic brainstem-derived neural stem cells expressing green fluorescent protein. Compared to other methods such as cannula insertion or tail-cuff, telemetry is advantageous to continuously monitor blood pressure and heart rate in freely moving animals. It is also capable of long term multiple data acquisitions. In spinal cord injured rats, basal cardiovascular data under unrestrained condition and autonomic dysreflexia in response to colorectal distension were successfully recorded. In addition, cardiovascular parameters before and after SCI can be compared in the same rat if a transmitter is implanted before a spinal cord transection. One limitation of the described telemetry procedure is that implantation in the femoral artery may influence the blood supply to the ipsilateral hindlimb.

We present a protocol for using a radio-telemetric system to record cardiovascular parameters in T4 spinal cord transected rats eight weeks after embryonic brainstem neural stem cell grafting into the lesion site. Telemetry is an advanced technique to accurately evaluate cardiovascular function in conscious freely moving spinal cord injured rats.

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter ...

Photothrombosis-induced Focal Ischemia as a Model of Spinal Cord Injury in Mice

Spinal cord injury (SCI) is a devastating clinical condition causing permanent changes in sensorimotor and autonomic functions of the spinal cord (SC) below the site of injury. The secondary ischemia that develops following the initial mechanical insult is a serious complication of the SCI and severely impairs the function and viability of surviving neuronal and non-neuronal cells in the SC. In addition, ischemia is also responsible for the growth of lesion during chronic phase of injury and interferes with the cellular repair and healing processes. Thus there is a need to develop a spinal cord ischemia model for studying the mechanisms of ischemia-induced pathology. Focal ischemia induced by photothrombosis (PT) is a minimally invasive and very well established procedure used to investigate the pathology of ischemia-induced cell death in the brain. Here, we describe the use of PT to induce an ischemic lesion in the spinal cord of mice. Following retro-orbital sinus injection of Rose Bengal, the posterior spinal vein and other capillaries on the dorsal surface of SC were irradiated with a green light resulting in the formation of a thrombus and thus ischemia in the affected region. Results from histology and immunochemistry studies show that PT-induced ischemia caused spinal cord infarction, loss of neurons and reactive gliosis. Using this technique a highly reproducible and relatively easy model of SCI in mice can be achieved that would serve the purpose of scientific investigations into the mechanisms of ischemia induced cell death as well as the efficacy of neuroprotective drugs. This model will also allow exploration of the pathological changes that occur following SCI in live mice like axonal degeneration and regeneration, neuronal and astrocytic Ca2+ signaling using two-photon microscopy.

Photothrombosis is a minimally invasive and highly reproducible procedure to induce focal ischemia in the spinal cord and serves as a model of spinal cord injury in mice.

Spinal cord injury (SCI) is a devastating clinical condition causing permanent changes in sensorimotor and autonomic functions of the spinal cord (SC) ...

A Neonatal Mouse Spinal Cord Compression Injury Model

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal cord. A major current area of research is focused on the mechanisms of adaptive plasticity that underlie spontaneous or induced functional recovery following SCI. Spontaneous functional recovery is reported to be greater early in life, raising interesting questions about how adaptive plasticity changes as the spinal cord develops. To facilitate investigation of this dynamic, we have developed a SCI model in the neonatal mouse. The model has relevance for pediatric SCI, which is too little studied. Because neural plasticity in the adult involves some of the same mechanisms as neural plasticity in early life1, this model may potentially have some relevance also for adult SCI. Here we describe the entire procedure for generating a reproducible spinal cord compression (SCC) injury in the neonatal mouse as early as postnatal (P) day 1. SCC is achieved by performing a laminectomy at a given spinal level (here described at thoracic levels 9-11) and then using a modified Yasargil aneurysm mini-clip to rapidly compress and decompress the spinal cord. As previously described, the injured neonatal mice can be tested for behavioral deficits or sacrificed for ex vivo physiological analysis of synaptic connectivity using electrophysiological and high-throughput optical recording techniques1. Earlier and ongoing studies using behavioral and physiological assessment have demonstrated a dramatic, acute impairment of hindlimb motility followed by a complete functional recovery within 2 weeks, and the first evidence of changes in functional circuitry at the level of identified descending synaptic connections1.

This article describes a method for generating a reproducible spinal cord compression injury (SCI) in the neonatal mouse. The model provides an advantageous platform for studying mechanisms of adaptive plasticity that underlie spontaneous functional recovery.

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal ...

Reproducible Arterial Denudation Injury by Infrarenal Abdominal Aortic Clamping in a Murine Model

Percutaneous vascular interventions uniformly result in arterial denudation injuries that subsequently lead to thrombosis and restenosis. These complications can be attributed to impairments in re-endothelialization within the wound margins. Yet, the cellular and molecular mechanisms of re-endothelialization remain to be defined. While several animal models to study re-endothelialization after arterial denudation are available, few are performed in the mouse because of surgical limitations. This undermines the opportunity to exploit transgenic mouse lines and investigate the contribution of specific genes to the process of re-endothelialization. Here, we present a step-by-step protocol for creating a highly reproducible murine model of arterial denudation injury in the infrarenal abdominal aorta using external vascular clamping. Immunocytochemical staining of injured aortas for fibrinogen and &#946;-catenin demonstrate the exposure of a pro-thrombotic surface and the border of intact endothelium, respectively. The method presented here has the advantages of speed, excellent overall survival rate, and relative technical ease, creating a uniquely practical tool for imposing arterial denudation injury in transgenic mouse models. Using this method, investigators may elucidate the mechanisms of re-endothelialization under normal or pathological conditions.

Understanding the cellular and molecular mechanisms of re-endothelialization following arterial denudation injury is of paramount importance in preventing thrombosis and restenosis of arteries. Here we describe a protocol for reproducible arterial denudation injury of the infrarenal abdominal aorta. The procedure was developed to investigate the underlying mechanisms that regulate endothelial regeneration using mouse models.