This work is funded by NIH RO1 NS 40433 (K.J.J.).

Toutes les procédures exécutées sont approuvés par l&#39;École de médecine institutionnel de protection des animaux et l&#39;utilisation Comité Université de l&#39;Indiana et suivent Institut national de lignes directrices de la santé. 1. Technique chirurgicale <ol><li> Maintenir une technique aseptique lors de cette procédure en utilisant des gants stériles, des instruments et un champ opératoire stérile selon les directives du NIH 25. Stériliser les outils avant de commencer la chirurgie par eux autoclavage (voir le tableau des réactifs spécifiques / Équipement pour la liste complète). Utiliser un stérilisateur à billes de verre pour stériliser les outils pendant l&#39;opération. </li></ol> 2. Anesthésie et préparation <ol><li> Anesthésier la souris dans une boîte d&#39;anesthésie avec un mélange de 0,9 L / min d&#39;oxygène et 2,5% d&#39;isoflurane utilisant un système de vaporisateur isoflurane vétérinaire. Assurez-vous que la souris ne répond pas à des changements dans la position du corps avant de le retirer de la boîte. </li><li> Appliquer une pommade ophtalmique à l&#39;mouLes yeux de soi pour les protéger du dessèchement. </li><li> Mettez le débit de gaz dans la zone du cône de nez. Placez la souris carrément sur son côté gauche sur un bloc couverte chauffée avec un tampon chirurgical et papier absorbant banc avec son nez et la bouche à l&#39;intérieur du cône. Surveiller en permanence le rythme respiratoire et le taux de la souris et ajuster les niveaux isoflurane selon les besoins (entre 2,5 à 3% d&#39;isoflurane) pour maintenir un niveau adéquat d&#39;anesthésie, et utiliser le pincement de l&#39;orteil réflexe pour confirmer la sédation totale. </li></ol> 3. Approche chirurgicale <ol><li> Aligner et concentrer le stéréoscope avec le champ opératoire. Ajuster le cône de nez et la bande vers le bas de sorte qu&#39;il est positionné le long du bord du champ visuel. </li><li> Avec la souris couché sur le côté gauche, la bande du bord de l&#39;oreille droite à le cône de nez, exposant la zone située derrière l&#39;oreille où l&#39;incision sera faite. Assurez-vous que la veine auriculaire postérieure se déplace horizontalement à travers l&#39;oreille. Notez que le placement correct de til animale et enregistrement de l&#39;oreille sont cruciales afin de trouver rapidement le nerf facial. </li><li> Mouiller la fourrure sur et derrière l&#39;oreille avec 70% d&#39;éthanol et de se raser le site chirurgical aide d&#39;un rasoir ou un scalpel lame. Prémouillage la fourrure facilite le rasage à cet endroit anatomique. </li><li> Nettoyer la peau avec une solution d&#39;iode, telles que le lavage chirurgical Betadine (7,5% de povidone-iode), suivie de 70% d&#39;éthanol. Répéter ce nettoyage deux fois plus pour désinfecter soigneusement la zone. </li><li> Pour déterminer où faire l&#39;incision, oligo la veine auriculaire postérieure de l&#39;oreille caudale vers la zone postérieure de la protubérance de l&#39;oreille. Avec des ciseaux de printemps, faire une incision de 4 mm 2 - 3 mm en arrière à la protubérance. </li><li> Disséquer par la graisse sous-cutanée et le fascia utilisant dissection. Evitez de couper direct avec les ciseaux, car les vaisseaux sanguins ou les tissus musculaires peuvent être facilement endommagés. </li><li> En cas de saignement, appliquer une pression sur le site chirurgical avec un coton-tige stérilependant au moins 30 sec. Si la perte de liquide importante se produit, injecter la souris par voie intraperitoneale avec 0,5 ml de solution saline stérile à 0,9% en utilisant une aiguille G 25 ou 27. </li><li> Utilisez plusieurs sites clés, le nerf spinal, canal de l&#39;oreille, et antérieure digastrique (décrit ci-dessous), pour localiser le nerf facial. Disséquer autour de ces sites jusqu&#39;à ce que les branches du nerf facial sont visualisés. Le nerf apparaît comme une structure solide blanc importante quand il se est révélé et une couche de fascia adhère à des structures sous-jacentes. <ol><li> Trouver le nerf spinal, qui se déplace de la partie caudale du crâne pour innerver le muscle trapèze, une fois que la graisse sous-cutanée et le fascia ont été disséqués. Le nerf facial est profonde du nerf spinal. </li><li> Trouvez le conduit auditif cartilagineux qui ressemble blanc nacré et peut être vu rostrale du nerf facial. </li><li> Trouver le ventre musculaire du muscle digastrique antérieure qui se trouve sur le dessus et caudal du nerf facial. </li></ol></li><li> Lorsque les principales branches du nerf facial sont visualisées, les tracer le dos pour trouver leur origine du foramen stylomastoïdien. En utilisant une pince fine pointe de Dumont # 5/45 pour maintenir le site chirurgical ouvert, avancer les conseils printemps ciseaux suivants le chemin de nerf, puis déplacez la pince le dos pour garder la zone nouvellement ouverte avancée. </li><li> Visualisez le tronc du nerf facial avec le zygomatique, buccale et branches mandibulaires marginaux à ce point. REMARQUE: La branche temporelle sera trouvé plus près des foramen. Les branches nerveuses mandibulaires marginaux dans ses parties supérieure et inférieure de plus près à la mâchoire, ainsi ces branches nerveuses ne seront pas visibles à ce niveau. <ol><li> Si l&#39;exécution d&#39;une transection du nerf, de stabiliser le nerf doucement avec les pinces fines de pointe et de couper le nerf avec les ciseaux à ressort. Éviter d&#39;appliquer trop de traction du nerf avec la pince pour empêcher avulsing le nerf partir du tronc cérébral. Pousserles souches de distance les uns des autres, ou couper et enlever une partie du nerf distale pour se assurer qu&#39;aucun reconnexion peut se produire. </li><li> Si l&#39;exécution d&#39;une lésion par écrasement, utiliser Dumont # 5/45 pince pour comprimer le nerf pendant 30 secondes en utilisant une pression constante pour rompre tous les axones, puis répétez cette cohue à un second angle perpendiculaire à la première place à l&#39;écrasement. Eviter d&#39;appliquer des quantités variables de pression pendant la cohue de 30 secondes, sinon la blessure ne sera pas uniforme entre les animaux. </li></ol></li></ol> 4. clôture et récupération <ol><li> Repositionner la graisse et les muscles sur les structures sous-jacentes. </li><li> Rapprocher les bords de l&#39;incision et de fermer la plaie en utilisant un clip de la plaie de 7,5 mm. Sutures ou de la colle est aussi acceptable pour la fermeture des plaies. Analgésiques post-opératoires peuvent être fournis à ce moment. </li><li> Retirer le ruban de l&#39;oreille de la souris. Éteignez le flux de l&#39;isoflurane et laissez la souris pour respirer l&#39;oxygène pur pendant 30 sec à 1 min. Place la souris dans une cage vide sans litière pour remettre de l&#39;anesthésie. </li><li> Lorsque la souris est récupéré, examiner son comportement pour des signes de confirmation de la paralysie faciale. Les moustaches seront paralysés et inclinés vers la joue, le nez sera dévié, et l&#39;œil ne clignote pas en réponse à une bouffée d&#39;air. </li><li> Animaux Maison conjointement après la chirurgie si elles sont des femmes. Évitez héberge des souris conjointement parce qu&#39;ils sont plus agressifs et ont tendance à retirer de force les clips de la plaie de leur compagnon de cage, ce qui conduit à l&#39;infection. Fournir analgésiques post-opératoires en ce moment, si nécessaire. </li><li> Surveiller les souris une fois par jour pendant plusieurs jours après l&#39;opération afin de se assurer qu&#39;aucune infection ou d&#39;autres complications se produisent après l&#39;opération. Retirer des agrafes 7-10 jours après la chirurgie se ils ne sont pas tombés sur leur propre. </li><li> Appliquer pommade ophtalmique lubrifiante à l&#39;œil touchée par jour pour prévenir les complications de la cornée, soit jusqu&#39;à ce que le réflexe de clignement des yeux est rerecouverts ou jusqu&#39;à l&#39;euthanasie. </li></ol>

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The authors have nothing to disclose.

The critical step for this protocol is positioning the mouse properly before surgery is begun. If the mouse is not lying flat on its side, the ear is not taped at the correct angle, or the incision is made in an incorrect location, then finding the facial nerve becomes much more difficult. When this technique is mastered, surgeries will take only minutes per mouse. 
Either sutures, glue, or wound clips can be used to close the wound. Wound clips are preferred because of the small size of incis...

De nombreux modèles de lésion nerveuse périphérique existent, mais celui qui se démarque pour l&#39;étude des motoneurones est le modèle nerf facial axotomie. Le nerf facial, également connu sous le nerf crânien VII, est originaire de la protubérance et innerve les muscles de l&#39;expression faciale 1,2. Dans ce protocole chirurgical, le nerf facial est exposé à sa sortie du foramen stylomastoïdien et soit coupé ou écrasé. La gravité des lésions nerveuses peuvent être classés suivant les trois classifications Sunderland, qui différencie la blessure sur la base de l&#39;intégrité de l&#39;axones, endonèvre, périnèvre et épinèvre, qui sont des couches de tissus conjonctifs qui enveloppent séquentiellement autour des faisceaux d&#39;axones. Dans la lésion par écrasement (axonotmésis), les axones sont sectionnés, mais le périnèvre et épinèvre sont préservés. Récupération fonctionnelle complète du visage écrasement du nerf se produit dans environ 11 jours parce que la gaine du nerf intacte sert de conduit dans lequel les axones repoussent 4,5. D&#39;D&#39;autre part, la blessure de coupe (neurotmésis), les axones et tous les trois couches de tissu conjonctif sont coupés, et l&#39;ensemble du nerf distal doit repousser pour restaurer la musculature innervation. Reconnexion chirurgicale de la épinèvre est souvent effectuée chez des patients humains atteints de lésions nerveuses transection, mais les résultats de récupération sont rarement optimale. Une étude plus approfondie est nécessaire pour comprendre pourquoi le nerf ne parvient pas à repousser à sa cible et quelles thérapies peut être utilisé pour améliorer et accélérer le processus de régénération. Il ya de nombreux avantages à l&#39;étude des lésions nerveuses en utilisant le modèle nerf facial axotomie. Tout d&#39;abord, la procédure nerf facial axotomie est rapide, facile et hautement reproductible; et la paralysie résultante des muscles faciaux ne affecte pas les fonctions vitales et est bien toléré par l&#39;animal. Parce que ce est un modèle de lésion du nerf crânien, l&#39;étude des corps cellulaires des neurones moteurs est simplifiée car les motoneurones résident dans une population relativement homogène dans ee moteur visage noyau dans le pont. La population ne diffère en fonction du modèle subnucléaire dans le noyau moteur facial, comme il ya sept sous-noyaux spécifiques à chaque innervant un groupe spécifique de muscles, donc différences subnucléaires en réponse à axotomie peut influer sur les résultats 2,6,7. Un avantage majeur du modèle de lésion du nerf facial est que le côté unaxotomized peut servir de contrôle interne associé parce que le innervation nerveuse est très symétrique et il n&#39;y a pas de diaphonie entre les noyaux moteurs du visage 8. Un autre avantage de l&#39;utilisation de ce procédé chirurgical est l&#39;absence d&#39;un traumatisme direct au SNC ou rupture de la barrière hémato-encéphalique 9. Les complications telles que des saignements excessifs et l&#39;infection sont rares à cette procédure. Diverses analyses peuvent être effectuées pour évaluer la réponse physiologique à une lésion nerveuse. La récupération du réflexe de clignement des yeux et l&#39;activité whiskers peut être utilisé comme un comportementalemesure de 10,11 fonctionnelle de récupération. L&#39;enregistrement vidéo de l&#39;activité vibrisses est actuellement la méthode la plus puissante pour détecter récupération de nerf facial innervation 12,13. Après l&#39;euthanasie, l&#39;analyse histologique du tronc cérébral peut être effectuée sur les corps cellulaires des neurones moteurs dans le noyau moteur facial. Le noyau moteur facial est subdivisée en sept sous-noyaux, chacun spécifique à certains muscles du visage, permettant pour examen différencié des réponses à une blessure 2,6. Motoneurones du visage peuvent être comptés pour quantifier la survie cellulaire, ou immunohistochimie peuvent être utilisés pour identifier des biomarqueurs et des populations de cellules spécifiques 14. Le noyau moteur facial peut être microdissection avec précision en utilisant capture laser pour l&#39;analyse moléculaire de la réponse cellulaire aux lésions nerveuses 15,16. Impacts du nerf facial axotomie peuvent être analysés dans le cortex moteur 17,18. En outre, le nerf peut être disséqué pour étudier la dégénérescence wallérienne 19 oula régénération des axones 20, et les muscles peuvent être retirés pour étudier jonctions neuromusculaires 21. Le nerf facial axotomie peut également être utilisé pour étudier les cellules d&#39;accompagnement centraux et périphériques gliales 22, 21 cibler la musculature et le système immunitaire de réponse de 23. Bien que beaucoup ait été accompli dans l&#39;étude du modèle de axotomie du nerf facial 24, une étude plus approfondie de lésion du nerf périphérique est nécessaire parce que les lésions nerveuses est un problème important pour les patients et les traitements actuels ne parviennent pas à produire des résultats optimaux. Ce modèle est un outil puissant pour l&#39;examen de la réponse physiologique à des lésions nerveuses et l&#39;analyse de l&#39;efficacité des thérapies de régénération nerveuse.

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			<td>Sterilize before use</td>
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			<td height="21" style="height:21px;width:381px;">0.9% Sodium Chloride Injection, USP</td>
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facial nerve axotomy in mice: a model to study motoneuron response to injury

Le but de ce protocole chirurgical est d&#39;exposer le nerf facial, qui innerve la musculature faciale, à sa sortie du foramen stylomastoïdien et coupé ou écraser pour induire une lésion nerveuse périphérique. Avantages de cette chirurgie sont sa simplicité, haute reproductibilité, et l&#39;absence d&#39;effet sur les fonctions vitales ou la mobilité de la paralysie faciale ultérieure, résultant ainsi en un résultat chirurgicale relativement faibles par rapport à d&#39;autres modèles de lésion nerveuse. Un avantage majeur de l&#39;utilisation d&#39;un modèle de lésion des nerfs crâniens est que les motoneurones résident dans une population relativement homogène dans le noyau moteur facial dans le pont, ce qui simplifie l&#39;étude des corps cellulaires des neurones moteurs. En raison du caractère symétrique de l&#39;innervation du nerf facial et le manque de diaphonie entre les noyaux moteurs du visage, l&#39;opération peut être effectuée de manière unilatérale avec le côté unaxotomized servant de témoin interne apparié. Une variété d&#39;analyses peut être effectuée après l&#39;opération de culss la réponse physiologique, dont les détails sont au-delà de la portée de cet article. Par exemple, la récupération de la fonction musculaire peut servir de marqueur comportementale pour réinnervation, ou les motoneurones peut être quantifiée pour mesurer la survie des cellules. En outre, les motoneurones peuvent être capturées avec précision en utilisant la microdissection laser pour l&#39;analyse moléculaire. Parce que l&#39;axotomie du nerf facial est peu invasive et bien toléré, il peut être utilisé sur une grande variété de souris génétiquement modifiées. En outre, ce modèle de la chirurgie peut être utilisé pour analyser l&#39;efficacité des traitements de lésion nerveuse périphérique. Lésion du nerf facial fournit un moyen d&#39;enquêter non seulement les motoneurones, mais aussi les réponses du microenvironnement central et périphérique gliale, le système immunitaire, et la cible musculature. Le modèle de lésion du nerf facial est un modèle de lésion nerveuse périphérique largement acceptée qui sert comme un outil puissant pour étudier les lésions nerveuses et la régénération.

Après le nerf facial axotomie est effectuée, la perte des motoneurones survient à la suite de la blessure. Motoneurone la survie après une blessure dépend de nombreuses variables, comme le sexe, l&#39;âge des animaux au moment de la chirurgie, et de la timepoint à laquelle les chiffres de motoneurones sont faites, et Moran et l&#39;examen Graeber 24 et Jinno et l&#39;examen Yamada 22 fois résumer les données de survie des motoneurones. Typiquement, environ 86% des motoneurones survivent à...

Watch this Scientific Journal Video about Facial Nerve Axotomy in Mice: A Model to Study Motoneuron Response to Injury at JoVE.com

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

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 ...

facial-nerve-axotomy-mice-model-to-study-motoneuron-response-to

Research

JoVE Journal

Medicine

12.7K vues.  Indiana University School of Medicine. 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. 

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

Pressure Controlled Ventilation to Induce Acute Lung Injury in Mice

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation (1-3, 5, 8, 26, 30, 33-36). ALI is defined by the acute onset of the disease, which leads to non-cardiac pulmonary edema and subsequent impairment of pulmonary gas exchange (36). We have developed a murine model of ALI by using a pressure-controlled ventilation to induce ventilator-induced lung injury (2). For this purpose, C57BL/6 mice are anesthetized and a tracheotomy is performed followed by induction of ALI via mechanical ventilation. Mice are ventilated in a pressure-controlled setting with an inspiratory peak pressure of 45 mbar over 1 - 3 hours. As outcome parameters, pulmonary edema (wet-to-dry ratio), bronchoalveolar fluid albumin content, bronchoalveolar fluid and pulmonary tissue myeloperoxidase content and pulmonary gas exchange are assessed (2). Using this technique we could show that it sufficiently induces acute lung inflammation and can distinguish between different treatment groups or genotypes (1-3, 5). Therefore this technique may be helpful for researchers who pursue molecular mechanisms involved in ALI using a genetic approach in mice with gene-targeted deletion.

A murine model for ventilator induced lung injury is an important tool to study an acute lung injury in vivo. Here, we report an easy applicable in situ model for acute lung injury using high-pressure mechanical ventilation to induce acute failure of the lung.

La ventilation à pression contrôlée pour induire lésion pulmonaire aiguë chez la souris

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged ...

Recherche

Médecine

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

Peripheral neuropathic pain is a severe chronic pain condition which may result from trauma to sensory nerves in the peripheral nervous system. The spared nerve injury (SNI) model induces symptoms of neuropathic pain such as mechanical allodynia i.e. pain due to tactile stimuli that do not normally provoke a painful response [1]. 
The SNI mouse model involves ligation of two of the three branches of the sciatic nerve (the tibial nerve and the common peroneal nerve), while the sural nerve is left intact [2]. The lesion results in marked hypersensitivity in the lateral area of the paw, which is innervated by the spared sural nerve. The non-operated side of the mouse can be used as a control. The advantages of the SNI model are the robustness of the response and that it doesn&#x2019;t require expert microsurgical skills.
The threshold for mechanical pain response is determined by testing with von Frey filaments of increasing bending force, which are repetitively pressed against the lateral area of the paw [3], [4]. A positive pain reaction is defined as sudden paw withdrawal, flinching and/or paw licking induced by the filament. A positive response in three out of five repetitive stimuli is defined as the pain threshold. 
As demonstrated in the video protocol, C57BL/6 mice experience profound allodynia as early as the day following surgery and maintain this for several weeks.

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

The Spared Nerve Injury animal model is described here as a mouse model of peripheral neuropathic pain following partial denervation of the sciatic nerve by lesioning the tibial and common peroneal nerve branches, leaving the remaining sural nerve intact. Behavioral modification resulting from mechanical allodynia is quantified by von Frey filaments.

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 ...

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 ...

Chronic Constriction Injury of the Rat's Infraorbital Nerve (IoN-CCI) to Study Trigeminal Neuropathic Pain

Animal models are important tools to study the pathophysiology and pharmacology of neuropathic pain. This manuscript describes the surgical and behavioral procedures to study trigeminal neuropathic pain in rats. To meet the specificity of trigeminal neuropathic pain syndromes, the infraorbital nerve (IoN) is subjected to a chronic constriction injury (CCI) by loosely ligating the nerve. An intra-orbital approach is presented here to expose and ligate the IoN in the orbital cavity. After IoN ligation, rats exhibit changes in spontaneous behavior and in response to von Frey hair stimulation that are indicative of persistent pain and mechanical allodynia. Two phases can be defined in the development of the behavioral changes. During the first week following IoN-CCI (phase 1), rats show an increased and asymmetric face grooming activity, i.e., with face wash strokes primarily directed to the nerve-injured IoN territory. A distinction is made between face grooming behavior that is part of a more general body grooming behavior, which remains largely unaffected by IoN-CCI, and face grooming that is neither preceded nor followed by body grooming, which is significantly increased after IoN-CCI. During this period, responsiveness to mechanical stimulation of the IoN territory is reduced. This hyporesponsiveness is abruptly replaced by an extreme hyperresponsiveness whereby even very weak stimulus intensities provoke nocifensive behavior (phase 2). The phenomenological similarities between these behavioral alterations and reported signs of facial pain (i.e., responses to noxious stimulation of the face) suggest the presence of dysesthesia/paresthesia and mechanical allodynia in the ligated IoN territory.

Chronic Constriction Injury of the Rat&#039;s Infraorbital Nerve IoN-CCI to Study Trigeminal Neuropathic Pain

This manuscript describes a rodent model to study trigeminal neuropathic pain. The methods described include surgical procedures to perform a chronic constriction injury of the rat&#8217;s infraorbital nerve and the post-surgical behavioral tests to measure the changes in spontaneous and evoked behavior that are indicative of persistent pain and allodynia.

Constriction chronique blessures de orbitaire du nerf de la Rat (ion-CCI) d&#39;étudier trijumeau douleur neuropathique

Animal models are important tools to study the pathophysiology and pharmacology of neuropathic pain. This manuscript describes the surgical and behavioral ...

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 ...

The Generation of Closed Femoral Fractures in Mice: A Model to Study Bone Healing

Bone fractures impose a tremendous socio-economic burden on patients, in addition to significantly affecting their quality of life. Therapeutic strategies that promote efficient bone healing are non-existent and in high demand. Effective and reproducible animal models of fractures healing are needed to understand the complex biological processes associated with bone regeneration. Many animal models of fracture healing have been generated over the years; however, murine fracture models have recently emerged as powerful tools to study bone healing. A variety of open and closed models have been developed, but the closed femoral fracture model stands out as a simple method for generating rapid and reproducible results in a physiologically relevant manner. The goal of this surgical protocol is to generate unilateral closed femoral fractures in mice and facilitate a post-fracture stabilization of the femur by inserting an intramedullary steel rod. Although devices such as a nail or a screw offer greater axial and rotational stability, the use of an intramedullary rod provides a sufficient stabilization for consistent healing outcomes without producing new defects in the bone tissue or damaging nearby soft tissue. Radiographic imaging is used to monitor the progression of callus formation, bony union, and subsequent remodeling of the bony callus. Bone healing outcomes are typically associated with the strength of the healed bone and measured with torsional testing. Still, understanding the early cellular and molecular events associated with fracture repair is critical in the study of bone tissue regeneration. The closed femoral fracture model in mice with intramedullary fixation serves as an attractive platform to study bone fracture healing and evaluate therapeutic strategies to accelerate healing.

The murine closed femoral fracture model is a powerful platform to study fracture healing and novel therapeutic strategies to accelerate bone regeneration. The goal of this surgical protocol is to generate unilateral closed femoral fractures in mice using an intramedullary steel rod to stabilize the femur.

La génération des Fractures fémorales fermées chez la souris : un modèle pour étudier la guérison osseuse

Bone fractures impose a tremendous socio-economic burden on patients, in addition to significantly affecting their quality of life. Therapeutic strategies ...

Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury

Myocardial ischemia and reperfusion injury (MIRI), induced by coronary heart disease (CHD), causes damage to the cardiomyocytes. Furthermore, evidence suggests that thrombolytic therapy or primary percutaneous coronary intervention (PPCI) does not prevent reperfusion injury. There is still no ideal animal model for MIRI. This study aims to improve the MIRI model in rats to make surgery easier and more feasible. A unique method for establishing MIRI is developed by using a soft tube during a key step of the ischemic period. To explore this method, thirty rats were randomly divided into three groups: sham group (n = 10); experimental model group (n = 10); and existing model group (n = 10). Findings of triphenyltetrazolium chloride staining, electrocardiography, and percent survival are compared to determine the accuracies and survival rates of the operations. Based on the study results, it has been concluded that the improved surgery method is associated with a higher survival rate, elevated ST-T segment, and larger infarct size, which is expected to mimic the pathology of MIRI better.

Myocardial ischemia-reperfusion model of rat heart is improved by using a self-made retractor, polyvinyl chloride tube, and a unique knotting method. Electrocardiogram, triphenyltetrazolium chloride and histological staining, and percent survival analysis results showed that the improved model group has higher success and survival rates than the already existing model group.

Modèle de rongeur amélioré de l’ischémie myocardique et de la lésion de reperfusion

Myocardial ischemia and reperfusion injury (MIRI), induced by coronary heart disease (CHD), causes damage to the cardiomyocytes. Furthermore, evidence ...