Les auteurs tiennent à remercier le Dr N. Banik et le Dr D. Mitchell pour leurs conseils dans l&#39;élaboration de ce modèle.

1. Préparation avant la lésion de la moelle épinière Les instruments chirurgicaux nécessaires à cette procédure sont scalpel, micros avec et sans dents, pinces hémostatiques, écarteurs autostatique, Rongeurs pointe fine, le conducteur de l&#39;aiguille, les sutures absorbables et applicateurs de clips de la peau. D&#39;autres fournitures chirurgicales requises sont draps chirurgicaux, draps stériles pour champ opératoire, des éponges de gaze, applicateurs coton-tip, et une feuille métallique. Autoclave des instruments chirurgicaux et des fournitures avant la chirurgie. Utilisez le jeu individuel d&#39;instruments et de fournitures pour un animal. Nettoyez la zone et un appareil (impacteur, de source de lumière, cadre stéréotaxique, billes de verre stérilisateurs et coussins chauffants) avec tampons imbibés d&#39;alcool chirurgical. Ouvrez les draps chirurgicaux et utiliser des gants stériles pour draper le champ opératoire en évitant soigneusement de contamination. Ouvrez les instruments individuels stérile et placer soigneusement ceux dans le domaine chirurgical. Couvrir les boutons et les poignées de thAppareil d&#39;électronique susceptible nécessaire au cours de la procédure avec la feuille métallique stérile. Mettre en marche la stérilisateur à billes de verre pour être prêt à l&#39;emploi au cours de la procédure. 2. Préparation des animaux Apportez les rats à la zone laboratoire quelques heures avant l&#39;intervention réelle. Administrer des médicaments de la douleur d&#39;au moins une heure avant la procédure prévue (généralement buprinorphine 1,5 ml de 0,006 mg / ml sous-cutanée). Administrer des antibiotiques préopératoires (typiquement Baytril 4 mg / kg sous-cutanée). Anesthésier les rats à l&#39;aide de 90 mg / kg de kétamine et d&#39;attendre jusqu&#39;à ce qu&#39;il n&#39;y a pas de réponse toe-pincement. Palper l&#39;apophyse épineuse plus important au niveau du rachis thoracique. Ce niveau correspond généralement à T10 apophyse épineuse. Marquez l&#39;emplacement du niveau prévu par rapport à T10. Dans notre laboratoire, nous effectuons une blessure T10. Le récit qui suit décrit la technique de T10 SCI. Raser un cm x 6 cm rectangle 3 longitudinalement et centrée au niveau T10. Nettoyer la peau trois fois wisolution de Betadine ème. Appliquer du lubrifiant ophtalmique sur chaque œil. Transférez le rat dans une position confortable pour le champ opératoire en évitant soigneusement de contamination. Insérer une sonde de température rectale à surveiller la température d&#39;âme et d&#39;ajuster en conséquence le chauffage pour maintenir la température des animaux est proche de la normale (~ 37,5 ° C) que possible. Recouvrir le rat avec un champ opératoire avec une fenêtre au-dessus du site chirurgical. 3. Procédure chirurgicale Commencez avec une participation d&#39;environ 4 cm incision à l&#39;aide d&#39;une lame # 10 centré sur la marque T10. Passez à disséquer patiemment fascia et les couches musculaires loin des apophyses épineuses T9-T11 et limbes. Placez les rétracteurs de rétracter les muscles et fascia loin de l&#39;os. Alors que la stabilisation de l&#39;apophyse épineuse de T9 fortement diviser le ligament interépineux entre T9 et T10 à l&#39;aide de ciseaux fins. De même stabiliser l&#39;apophyse épineuse T10 et diviser le ligament interépineux entre T10-T11. Utilisez une lentille de grossissement à compléterontte la division des ligaments tout au long du ligament jaune (Figure 1). Le sac dural est évidente une fois le ligament jaune est débranché. Utilisez rongeurs de pointe fine pour effectuer soigneusement laminectomie fragmentaire bilatérale au T10. Le plus grand soin est pris pour éviter une pression à la baisse sur le sac dural et blessures involontaires des conseils de rongeur. La lame et apophyse épineuse de T10 est complètement enlevé. Déplacez l&#39;animal en position sur plate-forme de stabilisation. Utiliser des brides de stabilisation pour immobiliser la colonne vertébrale par serrage des faces latérales du corps vertébral T11 suivie par les aspects latéraux du corps vertébral T9. Veillez à ne pas comprimer le rat dans la plate-forme avec les pinces de stabilisation car cela restreindrait espace pour les mouvements respiratoires et ajouter du stress indésirable l&#39;animal. Après avoir sécurisé les paramètres de la colonne vertébrale sur l&#39;impacteur contrôlé par ordinateur sont vérifiés. Nous utilisons généralement pointe de frappe de 3,0 mm à une spEED de 4 cm / s avec une profondeur de 2 mm et un temps de séjour de 0,3 s. Etendre la pointe du pendule et l&#39;abaisser jusqu&#39;à ce qu&#39;il touche la surface de la moelle. Rétracter la pointe et abaisser le dispositif de 2 mm vers la surface de la moelle épinière. Relâchez piston à 4 cm / s pour provoquer une contusion sévère blessure à la moelle épinière. Atteindre l&#39;hémostase avec juste assez de pression pour maintenir l&#39;applicateur coton-tige en place, en faisant attention de ne pas créer une pression inutile sur le cordon. muscle de suture et des couches de fascia avec un chiffre 8 point en faisant attention à ne pas tirer le trop serré par des sutures absorbables. Fermer la peau avec un minimum de 2 petites agrafes; jusqu&#39;à 4 ou 5 agrafes peuvent être utilisés si une partie de l&#39;incision restent ouvertes après les 2 ou 3 premières agrafes. 3. Soins post-procédure Placer les rats dans un environnement chaleureux d&#39;environ 33-35 ° C pendant 24 heures après la chirurgie. Cela implique un incubateur (alors qu&#39;ils sont inconscients) et un espace de cage chauffée dès qu&#39;ils commencent à bouger. Une fois que les rats sont entièrement awake, administrer 5 ml de solution saline, 1,5 ml (0,006 mg / ml) de buprinorphine, et 0,1 ml de Baytril tout sous-cutanée. Continuer avec buprinorphine voie sous-cutanée deux fois par jour pendant 24-48 premières heures et Baytril une fois par jour pendant 7 jours. Vessies doivent être exprimées manuellement trois fois par jour jusqu&#39;au retour de la fonction vésicale (&lt;2 ml d&#39;urine dans l&#39;expression du matin pendant 3 jours consécutifs). Les animaux doivent également être vérifiés durant cette période d&#39;infection (sang dans les urines, la couleur blanchâtre, ou une mauvaise odeur), diminution de l&#39;activité physique ou des problèmes de cicatrisation. Présence d&#39;une infection doit être contré avec un dosage augmenté (ou ré-initiation) d&#39;antibiotiques en consultation avec les vétérinaires locaux. Peser les rats commencent quotidien le lendemain de l&#39;intervention pour évaluer leur récupération.

<ol>
	<li>Blesch, A., Tuszynski, M. H. <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+injury:+plasticity,+regeneration+and+the+challenge+of+translational+drug+development.">Spinal cord injury: plasticity, regeneration and the challenge of translational drug development.</a> Trends Neurosci. 32, 41-47 (2009).</li><li>Dobkin, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Curiosity+and+cure:+translational+research+strategies+for+neural+repair-mediated+rehabilitation.">Curiosity and cure: translational research strategies for neural repair-mediated rehabilitation.</a> Dev. Neurobiol. 67, 1133-1147 (2007).</li><li>Fehlings, M. G., Cadotte, D. W., Fehlings, L. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+series+of+systematic+reviews+on+the+treatment+of+acute+spinal+cord+injury:+a+foundation+for+best+medical+practice.">A series of systematic reviews on the treatment of acute spinal cord injury: a foundation for best medical practice.</a> J. Neurotrauma. 28, 1329-1333 (2011).</li><li>Iseda, T., Okuda, T., Kane-Goldsmith, N., 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=Single,+high-dose+intraspinal+injection+of+chondroitinase+reduces+glycosaminoglycans+in+injured+spinal+cord+and+promotes+corticospinal+axonal+regrowth+after+hemisection+but+not+contusion.">Single, high-dose intraspinal injection of chondroitinase reduces glycosaminoglycans in injured spinal cord and promotes corticospinal axonal regrowth after hemisection but not contusion.</a> J. 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V., 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=Impact+speed+does+not+determine+severity+of+spinal+cord+injury+in+mice+with+fixed+impact+displacement.">Impact speed does not determine severity of spinal cord injury in mice with fixed impact displacement.</a> Journal of Neurotrauma. 26, 1395-1404 (2009).</li><li>Kwon, B. K., Hillyer, J., Tetzlaff, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Translational+research+in+spinal+cord+injury:+a+survey+of+opinion+from+the+SCI+community.">Translational research in spinal cord injury: a survey of opinion from the SCI community.</a> J. Neurotrauma. 27, 21-33 (2010).</li><li>Kwon, B. K., Okon, E. 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S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+extent+of+myelin+pathology+differs+following+contusion+and+transection+spinal+cord+injury.">The extent of myelin pathology differs following contusion and transection spinal cord injury.</a> J. Neurotrauma. 24, 1631-1646 (2007).</li><li>Talac, R., Friedman, J. A., Moore, M. 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=Animal+models+of+spinal+cord+injury+for+evaluation+of+tissue+engineering+treatment+strategies.">Animal models of spinal cord injury for evaluation of tissue engineering treatment strategies.</a> Biomaterials. 25, 1505-1510 (2004).</li><li>Tator, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+treatment+trials+in+human+spinal+cord+injury:+issues,+difficulties,+and+recommendations.">Review of treatment trials in human spinal cord injury: issues, difficulties, and recommendations.</a> Neurosurgery. 59, 957-982 (2006).</li></ol>

Aucun dispositif de transparence financière aucun de divulgation de financement.

Plusieurs nouveaux traitements ont récemment révélé prometteur dans le domaine de la recherche SCI. 3 évaluation minutieuse de ces traitements est essentielle dans le modèle cliniquement pertinent de la SCI à choisir des stratégies à fort potentiel de translation maximum. Un système de notation a été récemment mis au point pour évaluer la force des études précliniques. 9 Ce schéma a souligné l&#39;importance d&#39;utiliser le modèle de contusion sévère SCI. Nous décrivons ici ...

Choix du modèle de blessure appropriée est cruciale pour l&#39;évaluation préclinique de nouveaux traitements pour les blessures de la moelle épinière (SCI). 1,2,13 Dans un récent sondage de médecins et de scientifiques dans le domaine de modèle de contusion traumatisme neurologique, par opposition à hemisection ou modèles de section complète , a été universellement considéré comme cliniquement pertinente. 8 Cette opinion est fondée sur le constat que la majorité des blessures de la moelle épinière chez l&#39;homme est contondant dans la nature. 10 La biologie de contusion semble également être différents des modèles de Hémisection ou résection. 11 Iseda, et al. comparé l&#39;effet de l&#39;injection intra-rachidienne chondroitinase ABC sur neurorégénération séparément dans hemisection et modèles de contusions. 4 régénération axonale a été observée dans le pont neuronal dans hemisection mais pas le groupe SCI de contusion. Le hemisection ou modèles de section complète créent également des conditions connues pour exister que dans un très petit sous-ensemble de clinical circonstances. Par exemple, plusieurs chercheurs ont utilisé des interventions échafaudage à base d&#39;implantation dans la cavité lésion après hemisection ou section complète pour favoriser la régénération. 6 Cette approche devient cliniquement pertinente parce que la création d&#39;une cavité à l&#39;intérieur de la moelle épinière lésée est irréaliste et probablement contraire à l&#39;éthique. La variabilité de la récupération fonctionnelle reste un défi majeur pour les modèles de contusions. 5,12 Cette variabilité peut être minimisée par l&#39;utilisation de l&#39;impacteur contrôlé par ordinateur et à la stabilisation de la colonne vertébrale avant l&#39;impact pour la livraison de force uniforme à travers le volume de la moelle épinière en particulier les des voies motrices ventrale situés . Il faut noter que la plasticité et la contribution de garanties de la part des axones survivants est le mécanisme prédominant de récupération après une lésion de la moelle épinière. 1 variations conséquent, même mineures dans la technique de contusion peuvent donner des résultats très différents. À cette fin, nous avons développéun modèle de lésion de la moelle épinière sévère qui donne le volume de contusion cohérente et la récupération fonctionnelle comparable aux modèles de transsection. Ce modèle peut être utilisé pour étudier à la fois la neuroprotection et les stratégies de Neuroregeneration comme une preuve de concept de l&#39;efficacité du traitement.

<table border="1">
<tbody>
 <tr>
 <td>Instrument/Drugs</td>
 <td>Company</td>
 <td>Cat #</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Computer controlled impactor</td>
 <td>Leica or the Infinite Horizons (formerly OSU) impactor</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>Surgical instruments </td>
 </tr>
 <tr>
 <td>Scissors</td>
 <td>Fine Science Tools Inc
 </td>
 <td>14094-11 or 14060-09</td>
 <td></td>
 </tr>
 <tr>
 <td>Forceps</td>
 <td>Fine Science Tools Inc </td>
 <td>11006-12 and 11027-12 or 			11506-12</td>
 <td></td>
 </tr>
 <tr>
 <td>Hemostats</td>
 <td>Fine Science Tools Inc </td>
 <td>13009-12</td>
 <td></td>
 </tr>
 <tr>
 <td>Retractors</td>
 <td>Fine Science Tools Inc </td>
 <td>17011-10</td>
 <td></td>
 </tr>
 <tr>
 <td>Rongeurs</td>
 <td>Fine Science Tools Inc </td>
 <td>16020-14</td>
 <td></td>
 </tr>
 <tr>
 <td>Needle driver</td>
 <td>Fine Science Tools Inc </td>
 <td>12001-13</td>
 <td></td>
 </tr>
 <tr>
 <td>Stereotactic frame</td>
 <td> Leica or RWD Life Science Co. or
 TSE systems</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Buprinorphine</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Baytril</td>
 <td>Bayer</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Ketamine</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 </tbody>
</table>

a contusion model of severe spinal cord injury in rats

Le potentiel de translation de nouveaux traitements devrait être étudiée dans de graves blessures à la moelle épinière (SCI) des modèles de contusions. Une méthodologie détaillée est décrite afin d&#39;obtenir un modèle cohérent de graves SCI. Utilisation d&#39;un cadre stéréotaxique et de frappe commandé par ordinateur permet la création d&#39;un dommage reproductible. L&#39;hypothermie et les infections des voies urinaires posent des défis importants dans la période post-opératoire. Une surveillance attentive des animaux avec l&#39;enregistrement de poids quotidien et l&#39;expression de la vessie permet la détection précoce des complications post-opératoires. Les résultats fonctionnels de ce modèle de contusion sont équivalentes aux modèles de transsection. Le modèle de contusion peut être utilisé pour évaluer l&#39;efficacité de deux approches neuroprotectrices et neurorégénérative.

Lésion Volume Nous avons obtenu de grands volumes et cohérente des lésions en suivant la technique décrite ci-dessus. L&#39;utilisation d&#39;un Luxol rapide coloration au bleu un volume moyen de lésion de 2,04 mm 3 (CI 01.09 au 02.18 95%) (n = 5 animaux) a été obtenue. Figure 2 montre signifie volume de la lésion avec une coloration représentative en utilisant Luxol bleu rapide grâce à l&#39;épicentre de la lésion. Les scores f...

Watch this Scientific Journal Video about A Contusion Model of Severe Spinal Cord Injury in Rats at JoVE.com

A Contusion Model of Severe Spinal Cord Injury in Rats

Un modèle de contusion de la lésion médullaire sévère est décrite. Les étapes détaillées pré-opératoire, opératoires et post-opératoires sont décrits pour obtenir un modèle cohérent.

Un modèle de contusion de graves lésions de la moelle épinière chez les rats

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

a-contusion-model-of-severe-spinal-cord-injury-in-rats

Research

JoVE Journal

Medicine

30.2K vues.  Medical University of South Carolina. Un modèle de contusion de la lésion médullaire sévère est décrite. Les étapes détaillées pré-opératoire, opératoires et post-opératoires sont décrits pour obtenir un modèle cohérent.

Vidéo: A Contusion Model of Severe Spinal Cord Injury in Rats

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.

Aiguë et chronique Test tactile sensorielle après un traumatisme médullaire chez le rat

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

Recherche

Médecine

A Contusive Model of Unilateral Cervical Spinal Cord Injury Using the Infinite Horizon Impactor

While the majority of human spinal cord injuries occur in the cervical spinal cord, the vast majority of laboratory research employs animal models of spinal cord injury (SCI) in which the thoracic spinal cord is injured. Additionally, because most human cord injuries occur as the result of blunt, non-penetrating trauma (e.g. motor vehicle accident, sporting injury) where the spinal cord is violently struck by displaced bone or soft tissues, the majority of SCI researchers are of the opinion that the most clinically relevant injury models are those in which the spinal cord is rapidly contused.1 Therefore, an important step in the preclinical evaluation of novel treatments on their way to human translation is an assessment of their efficacy in a model of contusion SCI within the cervical spinal cord. Here, we describe the technical aspects and resultant anatomical and behavioral outcomes of an unilateral contusive model of cervical SCI that employs the Infinite Horizon spinal cord injury impactor.
Sprague Dawley rats underwent a left-sided unilateral laminectomy at C5. To optimize the reproducibility of the biomechanical, functional, and histological outcomes of the injury model, we contused the spinal cords using an impact force of 150 kdyn, an impact trajectory of 22.5&deg; (animals rotated at 22.5&deg;), and an impact location off of midline of 1.4 mm. Functional recovery was assessed using the cylinder rearing test, horizontal ladder test, grooming test and modified Montoya's staircase test for up to 6 weeks, after which the spinal cords were evaluated histologically for white and grey matter sparing.
The injury model presented here imparts consistent and reproducible biomechanical forces to the spinal cord, an important feature of any experimental SCI model. This results in discrete histological damage to the lateral half of the spinal cord which is largely contained to the ipsilateral side of injury. The injury is well tolerated by the animals, but does result in functional deficits of the forelimb that are significant and sustained in the weeks following injury. The cervical unilateral injury model presented here may be a resource to researchers who wish to evaluate potentially promising therapies prior to human translation.

A reliable and repeatable way to produce a cervical unilateral spinal cord injury using the Infinite Horizon impactor is described. The method takes advantage of a custom designed frame and clamp to stabilize the spine. The standardized procedure and biomechanical injury parameters result in sufficient and sustained injuries.

Un modèle de contusion unilatérale des blessures moelle épinière cervicale aide de l&#39;impacteur Infinite Horizon

While the majority of human spinal cord injuries occur in the cervical spinal cord, the vast majority of laboratory research employs animal models of ...

A Murine Model of Cervical Spinal Cord Injury to Study Post-lesional Respiratory Neuroplasticity

A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed to improve/ameliorate the respiratory failure following high cervical spinal cord injury (SCI). Here we propose a murine pre-clinical model of high SCI at the cervical 2 (C2) metameric level to study diverse post-lesional respiratory neuroplasticity. The technique consists of a surgical partial injury at the C2 level, which will induce a hemiparalysis of the diaphragm due to a deafferentation of the phrenic motoneurons from the respiratory centers located in the brainstem. The contralateral side of the injury remains intact and allows the animal recovery. Unlike other SCIs which affect the locomotor function (at the thoracic and lumbar level), the respiratory function does not require animal motivation and the quantification of the deficit/recovery can be easily performed (diaphragm and phrenic nerve recordings, whole body ventilation). This pre-clinical C2 SCI model is a powerful, useful, and reliable pre-clinical model to study various respiratory and non-respiratory neuroplasticity events at different levels (molecular to physiology) and to test diverse putative therapeutic strategies which might improve the respiration in SCI patients.

Respiratory failure is the leading cause of death following a cervical spinal cord injury. Having a reproducible, quantifiable, and reliable pre-clinical animal model of respiratory failure induced by a partial cervical injury will help to understand the subsequent respiratory and non-respiratory neuroplasticity and allow testing putative repair strategies.

Un modèle murin de la moelle épinière cervicale blessures à étude post-lésionnelle respiratoire neuroplasticité

A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed ...

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.

Contrôlée corticale modèle d&#39;impact pour 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, ...

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.

Un système de radio-télémétrique de surveiller la fonction cardiovasculaire chez le rat avec la moelle épinière Transection et embryonnaires souches neurales greffes cellulaires

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

Neural Stem Cell Transplantation in Experimental Contusive Model of Spinal Cord Injury

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can be used both to investigate the biological responses to injury and to test potential therapies. Contusion or compression injury delivered to the surgically exposed spinal cord are the most widely used models of the pathology. In this report the experimental contusion is performed by using the Infinite Horizon (IH) Impactor device, which allows the creation of a reproducible injury animal model through definition of specific injury parameters. Stem cell transplantation is commonly considered a potentially useful strategy for curing this debilitating condition. Numerous studies have evaluated the effects of transplanting a variety of stem cells. Here we demonstrate an adapted method for spinal cord injury followed by tail vein injection of cells in CD1 mice. In short, we provide procedures for: i) cell labeling with a vital tracer, ii) pre-operative care of mice, iii) execution of a contusive spinal cord injury, and iv) intravenous administration of post mortem neural precursors. This contusion model can be utilized to evaluate the efficacy and safety of stem cell transplantation in a regenerative medicine approach.

Spinal cord injury is a traumatic condition that causes severe morbidity and high mortality. In this work we describe in detail a contusion model of spinal cord injury in mice followed by a transplantation of neural stem cells.

Neural Transplantation de cellules souches dans la partie expérimentale Modèle contusion de la moelle épinière des blessures

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can ...

Calibrated Forceps Model of Spinal Cord Compression Injury

Compression injuries of the murine spinal cord are valuable animal models for the study of spinal cord injury (SCI) and spinal regenerative therapy. The calibrated forceps model of compression injury is a convenient, low cost, and very reproducible animal model for SCI. We used a pair of modified forceps in accordance with the method published by Plemel et al. (2008) to laterally compress the spinal cord to a distance of 0.35 mm. In this video, we will demonstrate a dorsal laminectomy to expose the spinal cord, followed by compression of the spinal cord with the modified forceps. In the video, we will also address issues related to the care of paraplegic laboratory animals. This injury model produces mice that exhibit impairment in sensation, as well as impaired hindlimb locomotor function. Furthermore, this method of injury produces consistent aberrations in the pathology of the SCI, as determined by immunohistochemical methods. After watching this video, viewers should be able to determine the necessary supplies and methods for producing SCI of various severities in the mouse for studies on SCI and/or treatments designed to mitigate impairment after injury.

Spinal cord injury models should be highly reproducible. We demonstrate that the calibrated forceps compression model of spinal cord injury is an easy to use surgical method for generating reproducible injuries to the murine spinal cord.

Calibré Forceps modèle de compression de la moelle épinière des blessures

Compression injuries of the murine spinal cord are valuable animal models for the study of spinal cord injury (SCI) and spinal regenerative therapy. The ...

Contrast Enhanced Ultrasound Imaging for Assessment of Spinal Cord Blood Flow in Experimental Spinal Cord Injury

Reduced spinal cord blood flow (SCBF) (i.e., ischemia) plays a key role in traumatic spinal cord injury (SCI) pathophysiology and is accordingly an important target for neuroprotective therapies. Although several techniques have been described to assess SCBF, they all have significant limitations. To overcome the latter, we propose the use of real-time contrast enhanced ultrasound imaging (CEU). Here we describe the application of this technique in a rat contusion model of SCI. A jugular catheter is first implanted for the repeated injection of contrast agent, a sodium chloride solution of sulphur hexafluoride encapsulated microbubbles. The spine is then stabilized with a custom-made 3D-frame and the spinal cord dura mater is exposed by a laminectomy at ThIX-ThXII. The ultrasound probe is then positioned at the posterior aspect of the dura mater (coated with ultrasound gel). To assess baseline SCBF, a single intravenous injection (400 &#181;l) of contrast agent is applied to record its passage through the intact spinal cord microvasculature. A weight-drop device is subsequently used to generate a reproducible experimental contusion model of SCI. Contrast agent is re-injected 15 min following the injury to assess post-SCI SCBF changes. CEU allows for real time and in-vivo assessment of SCBF changes following SCI. In the uninjured animal, ultrasound imaging showed uneven blood flow along the intact spinal cord. Furthermore, 15 min post-SCI, there was critical ischemia at the level of the epicenter while SCBF remained preserved in the more remote intact areas. In the regions adjacent to the epicenter (both rostral and caudal), SCBF was significantly reduced. This corresponds to the previously described &#8220;ischemic penumbra zone&#8221;. This tool is of major interest for assessing the effects of therapies aimed at limiting ischemia and the resulting tissue necrosis subsequent to SCI.

Contrast Enhanced Ultrasound imaging is a reliable in-vivo tool for quantifying spinal cord blood flow in an experimental rat spinal cord injury model. This paper contains a comprehensive protocol for application of this technique in association with a contusion model of thoracic spinal cord injury.

Contraste échographie amélioré pour l&#39;évaluation de la moelle épinière flux sanguin dans la partie expérimentale Traumatisme médullaire

Reduced spinal cord blood flow (SCBF) (i.e., ischemia) plays a key role in traumatic spinal cord injury (SCI) pathophysiology and is accordingly an ...

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.

Photothrombosis induite par ischémie focale comme un modèle de lésion médullaire chez la souris

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.

Un nouveau-né de la moelle épinière de souris Compression Modèle de lésion

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