Ce travail a été soutenu par la Fondation Lundbeck, la Fondation Carlsberg et Dagmar Marshall de la Fondation.

1. mesures de von Frey de base avant la chirurgie Pour la procédure de test de von Frey, s&#39;il vous plaît se référer à la section 5. 2. Anesthésie / préparation <ol><li> Anesthésier les animaux (injection intrapéritonéale d&#39;un mélange de kétamine et 100mg/kg de 15 mg / kg de xylazine). </li><li> Placez l&#39;animal dans un endroit tranquille jusqu&#39;à totalement anesthésié (par exemple recouverte d&#39;une serviette en papier). </li><li> Vérifiez réflexes en pinçant le bout de la queue et les pattes avec une paire de pincettes. Soyez sûr que les animaux ne réagissent pas avant de procéder. </li><li> Sous-cutanée d&#39;injecter (zone arrière de l&#39;épaule) 0.5ml solution saline isotonique avec des antibiotiques, par exemple, l&#39;ampicilline (pour éviter la déshydratation et de prévenir l&#39;infection, bien que cela est une procédure chirurgicale mineure). </li><li> Utiliser un rasoir électrique, raser le champ opératoire de légèrement en dessous de la zone du genou à la région de la hanche (pour les droitiers personnes du membre postérieur gauche est recommandé). </li><li> Appliquer une pommade ophtalmique pour les yeux avec un coton-tige-laine. </li><li> Placez l&#39;animal sur son côté droit et placer le membre postérieur gauche sur une petite plate-forme de la tenir élevée. Fixer la jambe avec du ruban adhésif. </li><li> Désinfecter le champ opératoire avec une alternance de gommages d&#39;éthanol et de l&#39;extérieur de la bétadine site chirurgical. </li></ol> 3. Chirurgie <ol><li> Localisez le genou avec le pouce de votre main gauche et utiliser un scalpel pour faire une application. Une incision cm dans le sens longitudinal proximal au genou. </li><li> Ouvrez la peau par dissection en utilisant la pointe d&#39;une paire de ciseaux stériles. </li><li> Séparez la couche musculaire par dissection juste à côté du vaisseau sanguin clairement visible, près de l&#39;os cuisse (fémur). Si fait correctement, les couches musculaires se séparer facilement sans aucun saignement, révélant le nerf sciatique droite en dessous des muscles. Si le saignement se produit par exemple par des dommages à un vaisseau sanguin près du genou, stérile à usage coton bourgeons ou des morceaux de regard pour absorber le sang. Appuyez sur jusqu&#39;à ce que le saignement s&#39;arrête. </li><li> Placez la souris sous un microscope stéréo et séparer délicatement les muscles avec une paire de pinces stériles (n ° 2) de visualiser le nerf sciatique. Rétracteurs peut également être appliquée. </li><li> Identifier la zone où les branches du nerf saphène du nerf sciatique. Le nerf sural est la plus petite des trois branches, ramification vers la droite dans la jambe gauche. </li><li> Appliquer de suture (6-0 sutures) autour des deux autres branches qui sont toujours en cours en parallèle (les nerfs tibial et fibulaire commun), en faisant bien attention de ne pas toucher la branche saphène. Ceci est une étape critique que le nerf sural doit être laissé intact. </li><li> Faire un noeud serré chirurgicale. Si le premier nœud est serré, les contractions du membre sera observée. </li><li> Prenez les nerfs à couper en dessous de la suture avec une paire de pinces (n ° 5) et couper les nerfs dessus et en dessous une pince à épiler avec une petite paire de ciseaux. Par-dessus la première coupe de la paire de pinces à épiler, en tirant des nerfs est évité. </li><li> Couper les extrémités de suture avec une paire de ciseaux micro et fermer doucement la couche musculaire. Ajouter une goutte de la lidocaïne sur la plaie et suture avec noeuds chirurgicales. </li></ol> 4. Après la chirurgie <ol><li> Vérifiez si la pommade oculaire est encore suffisante. </li><li> Placez la souris dans une cage propre sous une serviette de papier dans une posture confortable. Si la chambre est froide, placez un pad thermique sous une partie de la cage (seulement sous une partie de la cage de l&#39;animal doit être en mesure d&#39;échapper à une zone de froid si on préfère). </li><li> S&#39;assurer que l&#39;eau facilement accessible et Chow. </li></ol> 5. von Frey tests (de base et à partir du jour après la chirurgie) <ol><li> Placez la souris en rouge cylindres de plastique de couleur placée sur une table treillis métallique deux jours et un jour avant la chirurgie. S&#39;habituer pendant 15 min dans des bouteilles avant le test. La couleur rouge des cylindres permet aux souris de rapidement se détendre comme ils ne peuvent pas se voir et se trouvent dans une zone plus sombre. </li><li> Vérifiez que les souris sont calmes et appliquer von Frey filaments à la partie latérale de la patte: En commençant par le filament 0,02 g, appliquez d&#39;abord la force à la patte gauche cinq fois sur une période totale de 30 secondes (environ 2 secondes par stimulus) et de évaluer la réaction de la souris après chaque application. Répétez l&#39;opération avec le même filament et la patte gauche de toute autres souris, puis recommencer avec la patte droite de la première souris avant de passer à filament suivante, par exemple: <ul><li> Souris 1: patte gauche 5 fois avec filament 0,02 g </li><li> Souris 2: patte gauche 5 fois avec filament 0,02 g etc </li><li> Souris 1: patte droite 5 fois avec filament 0,02 g </li><li> Souris 2: patte droite 5 fois avec filament 0,02 g etc </li><li> Souris 1: patte gauche 5 fois avec filament 0,04 g </li><li> Souris 2: patte gauche 5 fois avec filament 0,04 g etc </li></ul></li><li> Réponse dans trois des cinq stimuli est considéré comme une réaction positive. Filaments-dessus SEUILSD peut être utilisée pour vérifier le niveau de seuil. Réponse = retrait de la patte soudaine, brutale broncher, patte soudaine lécher. </li></ol> 6. Les résultats représentatifs <img src="/files/ftp_upload/3092/3092fig1.jpg" alt="Figure 1" /> Figure 1. Von Frey tests sur C57BL / 6 ans des souris âgées de 8-10 semaines a été effectuée un jour avant l&#39;opération et à plusieurs reprises après la chirurgie. 4-8 animaux ont été inclus dans chaque groupe. Von Frey tests sur le côté opéré est représenté par le côté homolatéral et de contrôle non-exploité est représenté par controlatéral. Le lendemain de la chirurgie des animaux de développer une hypersensibilité significatif sur la patte exploité tandis que le non-exploité n&#39;est que légèrement affectée par rapport à des souris une opération fictive. (* &lt;0,05, ** &lt;0,01, *** &lt;0,001 par rapport ipsilatéral à controlatéral).

<ol>
	<li>Costigan, M., Scholz, J., Woolf, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuropathic+pain:+a+maladaptive+response+of+the+nervous+system+to+damage.">Neuropathic pain: a maladaptive response of the nervous system to damage.</a> Annu. Rev. Neurosci. 32, 1-32 (2009).</li><li>Decosterd, I., Woolf, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spared+nerve+injury:+an+animal+model+of+persistent+peripheral+neuropathic+pain.">Spared nerve injury: an animal model of persistent peripheral neuropathic pain.</a> Pain. 87, 149-158 (2000).</li><li>Bourquin, A. -. F., S&#252;veges, M., Pertin, M., Gilliar, N., Sardy, S., Davidson, A. C., Spahn, D. R., Decosterd, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+and+analysis+of+mechanical+allodynia-like+behavior+induced+by+spared+nerve+injury+(SNI)+in+the+mouse.">Assessment and analysis of mechanical allodynia-like behavior induced by spared nerve injury (SNI) in the mouse.</a> Pain. 122, 14.e1-14.e14 (2006).</li><li>Chaplan, S. R., Bach, F. W., Pogrel, J. W., Chung, J. M., Yaksh, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+assessment+of+tactile+allodynia+in+the+rat+paw.">Quantitative assessment of tactile allodynia in the rat paw.</a> J. Neurosci. Methods. 53, 55-63 (1994).</li><li>Bennett, G. J., Xie, Y. -. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+peripheral+mononeuropathy+in+rat+that+produces+disorders+of+pain+sensation+like+those+seen+in+man.">A peripheral mononeuropathy in rat that produces disorders of pain sensation like those seen in man.</a> Pain. 33, 87-107 (1988).</li><li>Seltzer, Z., Dubner, R., Shir, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+behavioral+model+of+neuropathic+pain+disorders+produced+in+rats+by+partial+sciatic+nerve+injury.">A novel behavioral model of neuropathic pain disorders produced in rats by partial sciatic nerve injury.</a> Pain. 43, 205-218 (1990).</li><li>Hargreaves, K., Dubner, R., Brown, F., Flores, C., Joris, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+and+sensitive+method+for+measuring+thermal+nociception+in+cutanous+hyperalgesia.">A new and sensitive method for measuring thermal nociception in cutanous hyperalgesia.</a> Pain. 32, 77-88 (1988).</li><li>Erichsen, H. K., Blackburn-Munro, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmacological+characterization+of+the+spared+nerve+injury+model+of+neuropathic+pain.">Pharmacological characterization of the spared nerve injury model of neuropathic pain.</a> Pain. 98, 151-161 (2002).</li></ol>

Aucun conflit d&#39;intérêt déclaré.

Les étapes critiques Dommages au nerf sural doit être évitée afin d&#39;étudier les changements pathologiques dans les lésions du nerf saphène intacte suivants pour les nerfs tibial et fibulaire commun. Les dommages collatéraux du nerf sural peut conduire à la paralysie et peut donc être visualisé comme glisser du membre opéré postérieurs. Seul le côté latéral de la patte est innervée par le nerf sural épargnée et, par conséquent, seule cette zone développe une neuropathie. Test d&#39;autres domaines, innervée par les nerfs sectionnés, peut fortement biais de l&#39;évaluation de seuil mécanique modifiée. D&#39;éventuelles modifications D&#39;autres types de ligatures peuvent être complémentaires en termes d&#39;étudier les conditions suivantes douleur pathologique des lésions nerveuses périphériques, tels que les blessures constriction chronique [5] ou la ligature partielle du nerf [6]. Chaque procédure expérimentale dans les résultats des changements phénotypiques distinctes qui devraient être considérés avant de post-opératoires d&#39;essai. Par ailleurs, d&#39;autres tests sensoriels tels que l&#39;hyperalgésie thermique peut être appliquée [7], bien que ce phénotype est moins robuste SNI suivant. Les applications futures Cette technique peut être utilisée pour les tests de médicaments altérant le développement ou le maintien de l&#39;allodynie mécanique [8]. Analyse du nerf sciatique, les ganglions de la racine dorsale (DRG) et / ou la moelle épinière lombaire permettre à la recherche des mécanismes moléculaires responsables du phénotype induit. L&#39;expérimentation animale a été réalisée selon bonnes pratiques de laboratoire en pleine conformité avec la réglementation danoise et européenne. Toutes les expériences ont été approuvés par l&#39;expérimentation animale danoises Inspection du ministère de la Justice (2006/561-1206 nombre permission).

<table border="1"><tbody><tr><td> Anesthésie: kétamine et de xylazine </td><td> Scalpel </td></tr><tr><td> Pommade ophtalmique </td><td> Paire de pinces nr. 2 </td></tr><tr><td> Rasoir électrique </td><td> Paire de pinces nr. 5 </td></tr><tr><td> Gants </td><td> Paire de ciseaux pour dissection </td></tr><tr><td> 70% (v / v) d&#39;éthanol </td><td> Ciseaux Micro </td></tr><tr><td> Ouate bourgeons / regards </td><td> 6,0 Prolène non résorbable </td></tr><tr><td> Microscope stéréo </td><td> 2 x porte-aiguilles </td></tr><tr><td> Ruban adhésif </td><td> Heat pad </td></tr><tr><td colspan="2"> von Frey filaments (0,02 - 2,0 g pour les souris) (Stoelting) </td></tr></tbody></table>

the spared nerve injury (sni) model of induced mechanical allodynia in mice

La douleur neuropathique périphérique est une affection chronique grave des douleurs qui peuvent résulter d&#39;un traumatisme des nerfs sensoriels dans le système nerveux périphérique. La blessure épargné nerveuses (SNI) du modèle induit des symptômes de la douleur neuropathique comme l&#39;allodynie mécanique à savoir la douleur due à des stimuli tactiles qui n&#39;ont normalement pas provoquer une réaction douloureuse [1]. Le modèle de souris SNI implique la ligature de deux des trois branches du nerf sciatique (nerf tibial et le nerf fibulaire commun), tandis que le nerf sural est laissé intact [2]. Les résultats des lésions dans l&#39;hypersensibilité marquée dans la zone latérale de la patte, qui est innervé par le nerf sural épargné. Le côté non opéré de la souris peut être utilisée comme contrôle. Les avantages du modèle SNI sont la robustesse de la réponse et qu&#39;il ne nécessite pas de compétences d&#39;experts de microchirurgie. Le seuil de réponse à la douleur mécanique est déterminée par des essais avec des filaments de von Frey de force de flexion croissante, qui sont répétitivement pressé contre la surface latérale de la patte [3], [4]. Une réaction à la douleur positif est défini comme retrait de la patte soudain broncher et / ou de patte léchage induit par le filament. Une réponse positive dans trois des cinq stimuli répétitifs est défini comme le seuil de douleur. Tel que démontré dans le protocole vidéo, souris C57BL / 6 expériences allodynie profonde dès le jour suivant la chirurgie et de maintenir ce pendant plusieurs semaines.

Watch this Scientific Journal Video about The Spared Nerve Injury SNI Model of Induced Mechanical Allodynia in Mice at JoVE.com

The Spared Nerve Injury SNI Model of Induced Mechanical Allodynia in Mice

Le modèle du nerf Epargnée blessures animal est décrit ici comme un modèle murin de douleur neuropathique périphérique suivantes dénervation partielle du nerf sciatique par lesioning les branches du tibia et du nerf péronier commun, laissant le nerf saphène reste intacte. Modification du comportement résultant d&#39;allodynie mécanique est quantifiée par des filaments de von Frey.

Les blessures du nerf Epargnée (SNI) Modèle d&#39;allodynie mécanique induite chez la souris

Peripheral neuropathic pain is a severe chronic pain condition which may result from trauma to sensory nerves in the peripheral nervous system. The spared ...

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Research

JoVE Journal

Medicine

The Spared Nerve Injury (SNI) Model of Induced Mechanical Allodynia in Mice

62.8K vues.  Aarhus University. Le modèle du nerf Epargnée blessures animal est décrit ici comme un modèle murin de douleur neuropathique périphérique suivantes dénervation partielle du nerf sciatique par lesioning les branches du tibia et du nerf péronier commun, laissant le nerf saphène reste intacte. Modification du comportement résultant d'allodynie mécanique est quantifiée par des filaments de von Frey.

Vidéo: The Spared Nerve Injury SNI Model of Induced Mechanical Allodynia in Mice

An in vivo Rodent Model of Contraction-induced Injury and Non-invasive Monitoring of Recovery

Muscle strains are one of the most common complaints treated by physicians. A muscle injury is typically diagnosed from the patient history and physical exam alone, however the clinical presentation can vary greatly depending on the extent of injury, the patient's pain tolerance, etc. In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies. Biological markers, such as serum creatine kinase levels, are typically elevated with muscle injury, but their levels do not always correlate with the loss of force production. This is even true of histological findings from animals, which provide a "direct measure" of damage, but do not account for all the loss of function. Some have argued that the most comprehensive measure of the overall health of the muscle in contractile force. Because muscle injury is a random event that occurs under a variety of biomechanical conditions, it is difficult to study. Here, we describe an in vivo animal model to measure torque and to produce a reliable muscle injury. We also describe our model for measurement of force from an isolated muscle in situ. Furthermore, we describe our small animal MRI procedure.

An in vivo Rodent Model of Contraction-induced Injury and Non-invasive Monitoring of Recovery

An in vivo animal model of injury is described. The method takes advantage of the subcutaneous position of the fibular nerve. Velocity, timing of muscle activation, and arc of motion are all pre-determined and synchronized using commercial software. Post injury changes are monitored in vivo using MR imaging/spectroscopy.

Une In vivo</emModèle de rongeur> de contraction induite par des blessures et de surveillance non invasive de récupération

Muscle strains are one of the most  common complaints treated by physicians. A muscle injury is typically diagnosed from the patient history and  physical ...

Recherche

Médecine

Ischemia-reperfusion Model of Acute Kidney Injury and Post Injury Fibrosis in Mice

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often unreported mortality rates that may confound analyses. Bilateral renal pedicle clamping is commonly used to induce IR-AKI, but differences between effective clamp pressures and/or renal responses to ischemia between kidneys often lead to more variable results. In addition, shorter clamp times are known to induce more variable tubular injury, and while mice undergoing bilateral injury with longer clamp times develop more consistent tubular injury, they often die within the first 3 days after injury due to severe renal insufficiency. To improve post-injury survival and obtain more consistent and predictable results, we have developed two models of unilateral ischemia-reperfusion injury followed by contralateral nephrectomy. Both surgeries are performed using a dorsal approach, reducing surgical stress resulting from ventral laparotomy, commonly used for mouse IR-AKI surgeries. For induction of moderate injury BALB/c mice undergo unilateral clamping of the renal pedicle for 26 min and also undergo simultaneous contralateral nephrectomy. Using this approach, 50-60% of mice develop moderate AKI 24 hr after injury but 90-100% of mice survive. To induce more severe AKI, BALB/c mice undergo renal pedicle clamping for 30 min followed by contralateral nephrectomy 8 days after injury. This allows functional assessment of renal recovery after injury with 90-100% survival. Early post-injury tubular damage as well as post injury fibrosis are highly consistent using this model.

We describe models of moderate and severe ischemia-reperfusion-induced kidney injury in which the mice undergo unilateral renal pedicle clamping followed by simultaneous or delayed contralateral nephrectomy, respectively. These models consistently give rise to renal dysfunction and post-injury fibrosis, but injury severity and survival are dependent on mouse background, age and surgical equipment.

Ischémie-reperfusion modèle de lésions rénales aiguës et post blessures fibrose chez la souris

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often ...

Tibial Nerve Transection - A Standardized Model for Denervation-induced Skeletal Muscle Atrophy in Mice

The tibial nerve transection model is a well-tolerated, validated, and reproducible model of denervation-induced skeletal muscle atrophy in rodents. Although originally developed and used extensively in the rat due to its larger size, the tibial nerve in mice is big enough that it can be easily manipulated with either crush or transection, leaving the peroneal and sural nerve branches of the sciatic nerve intact and thereby preserving their target muscles. Thus, this model offers the advantages of inducing less morbidity and impediment of ambulation than the sciatic nerve transection model and also allows investigators to study the physiologic, cellular and molecular biologic mechanisms regulating the process of muscle atrophy in genetically engineered mice. The tibial nerve supplies the gastrocnemius, soleus and plantaris muscles, so its transection permits the study of denervated skeletal muscle composed of fast twitch type II fibers and/or slow twitch type I fibers. Here we demonstrate the tibial nerve transection model in the C57Black6 mouse. We assess the atrophy of the gastrocnemius muscle, as a representative muscle, at 1, 2, and 4 weeks post-denervation by measuring muscle weights and fiber type specific cross-sectional area on paraffin-embedded histologic sections immunostained for fast twitch myosin.

The tibial nerve transection model is a well-tolerated, validated, and reproducible model of skeletal muscle atrophy. The model surgical protocol is described and demonstrated in C57Black6 mice. &#160;

Tibial Nerve Transection - un modèle standardisé pour dénervation induit l&#39;atrophie musculaire chez les souris

The tibial nerve transection model is a well-tolerated, validated, and reproducible model of denervation-induced skeletal muscle atrophy in rodents. ...

The Sciatic Nerve Cuffing Model of Neuropathic Pain in Mice

Neuropathic pain arises as a consequence of a lesion or a disease affecting the somatosensory system. This syndrome results from maladaptive changes in injured sensory neurons and along the entire nociceptive pathway within the central nervous system. It is usually chronic and challenging to treat. In order to study neuropathic pain and its treatments, different models have been developed in rodents. These models derive from known etiologies, thus reproducing peripheral nerve injuries, central injuries, and metabolic-, infectious- or chemotherapy-related neuropathies. Murine models of peripheral nerve injury often target the sciatic nerve which is easy to access and allows nociceptive tests on the hind paw. These models rely on a compression and/or a section. Here, the detailed surgery procedure for the &#34;cuff model&#34; of neuropathic pain in mice is described. In this model, a cuff of PE-20 polyethylene tubing of standardized length (2 mm) is unilaterally implanted around the main branch of the sciatic nerve. It induces a long-lasting mechanical allodynia, i.e., a nociceptive response to a normally non-nociceptive stimulus that can be evaluated by using von Frey filaments. Besides the detailed surgery and testing procedures, the interest of this model for the study of neuropathic pain mechanism, for the study of neuropathic pain sensory and anxiodepressive aspects, and for the study of neuropathic pain treatments are also discussed.

Neuropathic pain is a consequence of a lesion or disease affecting the somatosensory system. The &#8220;cuff model&#8221; of neuropathic pain in mice consists of the implantation of a polyethylene cuff around the main branch of the sciatic nerve. Mechanical allodynia is tested using von Frey filaments.

Le nerf sciatique menottes modèle de douleur neuropathique chez les souris

Neuropathic pain arises as a consequence of a lesion or a disease affecting the somatosensory system. This syndrome results from maladaptive changes in ...

Facial Nerve Axotomy in Mice: A Model to Study Motoneuron Response to Injury

The goal of this surgical protocol is to expose the facial nerve, which innervates the facial musculature, at its exit from the stylomastoid foramen and either cut or crush it to induce peripheral nerve injury. Advantages of this surgery are its simplicity, high reproducibility, and the lack of effect on vital functions or mobility from the subsequent facial paralysis, thus resulting in a relatively mild surgical outcome compared to other nerve injury models. A major advantage of using a cranial nerve injury model is that the motoneurons reside in a relatively homogenous population in the facial motor nucleus in the pons, simplifying the study of the motoneuron cell bodies. Because of the symmetrical nature of facial nerve innervation and the lack of crosstalk between the facial motor nuclei, the operation can be performed unilaterally with the unaxotomized side serving as a paired internal control. A variety of analyses can be performed postoperatively to assess the physiologic response, details of which are beyond the scope of this article. For example, recovery of muscle function can serve as a behavioral marker for reinnervation, or the motoneurons can be quantified to measure cell survival. Additionally, the motoneurons can be accurately captured using laser microdissection for molecular analysis. Because the facial nerve axotomy is minimally invasive and well tolerated, it can be utilized on a wide variety of genetically modified mice. Also, this surgery model can be used to analyze the effectiveness of peripheral nerve injury treatments. Facial nerve injury provides a means for investigating not only motoneurons, but also the responses of the central and peripheral glial microenvironment, immune system, and target musculature. The facial nerve injury model is a widely accepted peripheral nerve injury model that serves as a powerful tool for studying nerve injury and regeneration.

We present a surgical protocol detailing how to perform a cut or crush axotomy on the facial nerve in the mouse. The facial nerve axotomy can be employed to study the physiological response to nerve injury and test therapeutic techniques.

Visage axotomie des nerfs chez la souris: Un modèle pour étudier motoneurone réponse à une blessure

The goal of this surgical protocol is to expose the facial nerve, which innervates the facial musculature, at its exit from the stylomastoid foramen and ...

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 Repetitive Concussive Head Injury Model in Mice

Despite the concussion/ mild traumatic brain injury (mTBI) being the most frequent occurrence of traumatic brain injury, there is still a lack of knowledge on the injury and its effects. To develop a better understanding of concussions, animals are often used because they provide a controlled, rigorous, and efficient model. Studies have adapted traditional animal models to perform mTBI to stimulate mild injury severity by changing the injury parameters. These models have been used because they can produce morphologically similar brain injuries to the clinical condition and provide a spectrum of injury severities. However, they are limited in their ability to present the identical features of injuries in patients. Using a traditional impact system, a repetitive concussive injury (rCHI) model can induce mild to moderate human-like concussion. The injury degree can be determined by measuring the period of loss of consciousness (LOC) with a sign of a transient termination of breathing. The rCHI model is beneficial to use for its accuracy and simplicity in determining mTBI effects and potential treatments.

Concussion presents the most common type of traumatic brain injury. Therefore, a repetitive concussive animal model, which replicates the important features of an injury in patients, may provide a means to study concussion in a rigorous, controlled, and efficient manner.

Une blessure à la tête modèle Répétitive commotionnant chez la souris

Despite the concussion/ mild traumatic brain injury (mTBI) being the most frequent occurrence of traumatic brain injury, there is still a lack of ...

Induction of Accelerated Atherosclerosis in Mice: The "Wire-Injury" Model

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. Moreover, by rupture of the defective vascular wall, atherosclerosis induces occlusive thrombus formation, which represents the main cause of myocardial infarction or stroke and the most frequent cause of death. Despite the advances in the cardiovascular field, many questions remain unanswered, and additional basic research is essential to improve our understanding of the molecular mechanisms during atherosclerosis and its effects. Due to limited clinical studies, there is a need for representative animal models recreating atherosclerotic conditions such as neointima formation after stent implantation, balloon angioplasty, or endarterectomy. Since the mouse presents many advantages and is the most frequently used model for studying molecular processes, the current study proposes an invasive procedure of endothelial denudation, also known as the wire-injury model, which is representative of the human condition of neointima formation in arteries after revascularization procedures.

Induction of Accelerated Atherosclerosis in Mice: The &quot;Wire-Injury&quot; Model

This study describes an invasive procedure for the induction of accelerated atherosclerosis in mice. In comparison to other methods using electric- or cryo-induced injury, mechanical-induced injury mimics the human condition of restenosis after revascularization therapies and is ideal for the study of the molecular mechanisms involved.

Induction de l’athérosclérose accélérée chez les souris : le modèle « Wire-Injury »

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. ...

A Tissue Displacement-based Contusive Spinal Cord Injury Model in Mice

Producing a consistent and reproducible contusive spinal cord injury (SCI) is critical to minimizing behavioral and histological variabilities between experimental animals. Several contusive SCI models have been developed to produce injuries using different mechanisms. The severity of the SCI is based on the height that a given weight is dropped, the injury force, or the spinal cord displacement. In the current study, we introduce a novel mouse contusive SCI device, the Louisville Injury System Apparatus (LISA) impactor, which can create a displacement-based SCI with high injury velocity and accuracy. This system utilizes laser distance sensors combined with advanced software to produce graded and highly-reproducible injuries. We performed a contusive SCI at the 10th thoracic vertebral (T10) level in mice to demonstrate the step-by-step procedure. The model can also be applied to the cervical and lumbar spinal levels.

We introduce a tissue displacement-based contusive spinal cord injury model that can produce a consistent contusive spinal cord injury in adult mice.

Un modèle de lésion de la moelle épinière à base de déplacement tissulaire à base de tissus chez les souris

Producing a consistent and reproducible contusive spinal cord injury (SCI) is critical to minimizing behavioral and histological variabilities between ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

Mesure de la contractilité isométrique de l’artère mésentérique de souris à l’aide de fil myographie

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...