Diese Arbeit wurde von der Lundbeck-Stiftung, die Carlsberg-Stiftung und Dagmar Marshall-Stiftung unterstützt.

1. von Frey Baseline-Messungen vor der Operation Für von Frey Testverfahren finden Sie in Abschnitt 5. 2. Anästhesie / der Zubereitung <ol><li> Anesthetize der Tiere (intraperitoneale Injektion einer Mischung von 100mg/kg Ketamin und 15 mg / kg Xylazin). </li><li> Legen Sie das Tier an einem ruhigen Ort, bis sie vollständig narkotisiert (zB mit einem Papiertuch abgedeckt). </li><li> Überprüfen Reflexe durch Kneifen der Spitze des Schwanzes und der Pfoten mit einer Pinzette. Achten Sie darauf, dass die Tiere nicht mehr reagiert, bevor Sie fortfahren werden. </li><li> Subkutan zu injizieren (zurück Schulterbereich) 0,5 ml isotonischer Kochsalzlösung mit Antibiotika, zB Ampicillin (um Dehydration zu vermeiden und eine Infektion zu verhindern, obwohl dies einem kleinen operativen Eingriff). </li><li> Mit einem elektrischen Rasierer rasieren das Operationsfeld von leicht unterhalb des Knies Bereich der Hüft-Bereich (für Rechtshänder die linke Hinterbein wird empfohlen). </li><li> Bewerben Augensalbe in die Augen mit einem Wattestäbchen. </li><li> Legen Sie das Tier auf seiner rechten Seite und legen Sie den linken Hinterlauf auf einer kleinen Plattform zu halten, erhöht. Sichern Sie das Bein mit Klebeband. </li><li> Desinfizieren Sie das Operationsfeld mit wechselnden scrubs von Ethanol und betadine von OP-Gebiet aus. </li></ol> 3. Chirurgie <ol><li> Suchen Sie die Knie mit dem Daumen der linken Hand und mit einem Skalpell eine App zu machen. 1 cm Schnitt in Längsrichtung proximal des Knies. </li><li> Öffnen Sie die Haut durch stumpfe Präparation mit der Spitze ein Paar sterile Schere. </li><li> Trennen Sie die Muskelschicht durch stumpfe Präparation direkt neben dem deutlich sichtbaren Blutgefäße, die Oberschenkelknochen (Femur) schließen. Wenn es richtig gemacht, wird die Muskelschichten leicht ohne Blutung getrennt und enthüllt die Ischiasnerv rechts unterhalb der Muskeln. Kommt es zu Blutungen zB durch Beschädigung eines Blutgefäßes in der Nähe des Knies, verwenden Sie sterile Watte Knospen oder Stücke Blick auf das Blut aufzufangen. Drücken, bis die Blutung aufhört. </li><li> Platzieren Sie die Maus unter einem Stereomikroskop und vorsichtig die Muskeln mit einem Paar sterile Pinzette (nr. 2), um den Ischiasnerv zu visualisieren. Retraktoren kann auch angewendet werden. </li><li> Identifizieren Sie die Fläche, wo der N. suralis Zweige von den Ischiasnerv. Der N. suralis ist die kleinste der drei Zweige, Verzweigung nach rechts in das linke Bein. </li><li> Bewerben Naht (6-0 Faden) um die beiden anderen Zweige, die noch ausgeführt werden parallel (die Tibia und gemeinsame peroneus), wobei sehr vorsichtig, nicht auf die suralis Zweig berühren. Dies ist ein kritischer Schritt, da der Nervus suralis ist nach links vollkommen intakt sein. </li><li> Machen Sie einen engen chirurgischen Knoten. Wenn der erste Knoten ist eng, wird Kontraktionen des Körpers beobachtet werden. </li><li> Besorgen Sie sich die Nerven unterhalb der Naht mit einer Pinzette (nr. 5) geschnitten werden und schneiden Sie die Nerven ober-und unterhalb einer Pinzette mit einer kleinen Schere. Mit ersten Schnitt oberhalb der Pinzette, zieht der Nerven vermieden wird. </li><li> Cut off Fadenenden mit einem Paar von Mikro-Schere und sanft in der Nähe der Muskelschicht. Geben Sie einen Tropfen von Lidocain auf die Wunde und Naht mit chirurgischen Knoten. </li></ol> 4. Nach der Operation <ol><li> Prüfen Sie, ob Augensalbe noch ausreicht. </li><li> Platzieren Sie die Maus in einem sauberen Käfig unter einem Papiertuch in einer bequemen Haltung. Wenn der Raum kalt ist, legen Sie ein Heizkissen unter einem Teil des Käfigs (nur unter Teil des Käfigs als das Tier sollte in der Lage zu einem kälteren Bereich, wenn sie bevorzugt zu entkommen). </li><li> Stellen Sie sicher, leicht zugänglich Wasser und Futter. </li></ol> 5. von Frey-Tests (baseline, und ab dem Tag nach der Operation) <ol><li> Legen Sie die Maus in roten Kunststoff-Zylinder auf einem Drahtnetz Tabelle 2 Tage und 1 Tag vor der Operation gestellt. Gewöhnen für 15 min in Zylinder vor dem Test. Die rote Farbe der Zylinder hilft den Mäusen zu schnell entspannen, da sie nicht sehen können, sich gegenseitig und sind in einem dunkleren Bereich. </li><li> Stellen Sie sicher, dass die Mäuse ruhig sind und gelten von Frey Filamente an den seitlichen Teil der Pfote: Beginnend mit dem 0,02 g Filament, erste Kraft auf der linken Pfote fünfmal über einen Zeitraum von insgesamt 30 Sekunden (ca. 2 Sekunden pro Reiz) und gauge der Maus die Reaktion nach jeder Anwendung. Wiederholen Sie mit dem gleichen Faden und die linke Pfote eines anderen Mäuse, und dann wieder von vorne anfangen mit der rechten Pfote der ersten Maus, bevor sie zu den nächsten Faden, z. B.: <ul><li> Maus 1: linke Pfote 5 mal mit Filament 0,02 g </li><li> Maus 2: linke Pfote 5 mal mit Filament 0,02 g etc. </li><li> Maus 1: rechte Pfote 5 mal mit Filament 0,02 g </li><li> Maus 2: rechte Pfote 5 mal mit Filament 0,02 g etc. </li><li> Maus 1: linke Pfote 5 mal mit Filament 0,04 g </li><li> Maus 2: linke Pfote 5 mal mit Filament 0,04 g etc. </li></ul></li><li> Response in drei von fünf Reize wird als positive Reaktion angesehen. Filaments oben threshold angewendet, um den Schwellenwert zu überprüfen. Response = plötzliche Pfote Rückzug, plötzlicher Wimper zu zucken, plötzliche Pfote leckt. </li></ol> 6. Repräsentative Ergebnisse <img src="/files/ftp_upload/3092/3092fig1.jpg" alt="Abbildung 1" /> Abbildung 1. Von Frey Tests auf C57BL / 6 Mäusen Alter 8-10 Wochen alt wurde durchgeführt, 1 Tag vor der Operation und immer wieder nach der Operation. 4-8 Tiere wurden in jeder Gruppe enthalten. Von Frey Tests auf der operierten Seite ist durch ipsilateral vertreten und die nicht operierte Kontrolle Seite ist durch kontralaterale vertreten. Der Tag nach der Operation die Tiere entwickeln signifikanter Überempfindlichkeit auf der operierten Pfote, während die nicht betrieben wird nur geringfügig beeinträchtigt gegenüber scheinoperierten Mäusen. (* &lt;0,05, ** &lt;0,01, *** &lt;0,001, ipsilateral gegenüber kontralateral).

<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>

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Kritische Schritte Schäden an der Nervus suralis sollte vermieden werden, um pathologische Veränderungen in den intakten N. suralis nach Verletzungen der Tibia und gemeinsame peroneus zu studieren. Kollateralschäden an der N. suralis kann zu Lähmungen führen und damit sichtbar gemacht werden wie das Ziehen des operierten Hinterbein. Nur der lateralen Seite der Pfote wird durch die verschont suralis innerviert und damit entwickelt sich nur dieser Bereich Neuropathie. Testen anderen Bereichen, durch die durchtrennten Nerven innerviert, kann stark spannen die Auswertung der veränderten mechanischen Schwelle. Mögliche Änderungen Andere Arten von Ligationen können Zusatzprogramme werden in Bezug auf das Studium pathologischer Schmerzzustände folgenden peripheren Nervenverletzung, wie chronische Verengung Verletzungen [5] oder teilweise Nerven Ligation [6]. Jede experimentelle Vorgehen führt zu deutlichen phänotypische Veränderungen, die vor dem postoperativen Tests in Betracht gezogen werden sollte. Darüber hinaus können auch andere sensorische Tests wie thermische Hyperalgesie [7] angewendet werden, obwohl dieser Phänotyp ist weniger robust folgenden SNI. Zukünftige Anwendungen Diese Technik kann für die Prüfung von Medikamenten verändern die Entwicklung oder Wartung von mechanischer Allodynie eingesetzt werden [8]. Die Analyse der Ischiasnerv, damit die Spinalganglien (DRG) und / oder der Lendenwirbelsäule Rückenmark Erforschung der molekularen Mechanismen, die für die induzierte Phänotyp. Tierversuche wurde nach guter Laborpraxis in voller Übereinstimmung mit dem dänischen und europäischen Vorschriften durchgeführt. Alle Experimente wurden von der dänischen Tierversuche Inspectorate unter dem Ministry of Justice (Erlaubnis Nummer 2006/561-1206) zugelassen.

<table border="1"><tbody><tr><td> Anästhesie: Ketamin und Xylazin </td><td> Skalpell </td></tr><tr><td> Augensalbe </td><td> Pinzette nr. 2 </td></tr><tr><td> Trockenrasierer </td><td> Pinzette nr. 5 </td></tr><tr><td> Handschuhe </td><td> Schere für stumpfe </td></tr><tr><td> 70% (v / v) Ethanol </td><td> Micro Schere </td></tr><tr><td> Cotton-Wool-Knospen / Blick </td><td> 6,0 Prolene nicht-resorbierbares Nahtmaterial </td></tr><tr><td> Stereo-Mikroskop </td><td> 2 x Nadelhalter </td></tr><tr><td> Klebeband </td><td> Heizkissen </td></tr><tr><td colspan="2"> von Frey Filamente (0,02 bis 2,0 g für Mäuse) (Stölting) </td></tr></tbody></table>

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

Periphere neuropathische Schmerzen ist eine schwere chronische Schmerzen Bedingung, die von einem Trauma zu sensiblen Nerven in den peripheren Nervensystems führen kann. Das erspart Nervenverletzung (SNI) Modell induziert Symptome der neuropathischen Schmerzen wie mechanische Allodynie, dh Schmerzen durch taktile Reize, die normalerweise nicht provozieren eine schmerzhafte Reaktion [1]. Die SNI Mausmodell handelt Ligation von zwei der drei Zweige der Ischiasnerv (Nervus tibialis und der N. peronaeus), während der N. suralis ist intakt [2]. Die Läsion Ergebnisse in deutlichem Überempfindlichkeit im seitlichen Bereich der Pfote, die durch die verschont suralis innerviert ist. Die nicht operierten Seite der Maus können als Kontrolle verwendet werden. Die Vorteile des SNI-Modell sind die Robustheit der Reaktion, und dass es nicht erforderlich Experte mikrochirurgische Fähigkeiten. Die Schwelle für mechanische Schmerzreaktion wird durch Tests mit von Frey Filamente der zunehmenden Biegekraft, die wiederholt gegen die seitlichen Bereich der Pfote gedrückt werden bestimmt [3], [4]. Eine positive Schmerzreaktion als plötzlich Pfote Rückzug definiert, der Wimper zu zucken und / oder Pfote leckt induziert durch das Filament. Eine positive Reaktion in drei von fünf repetitive Reize als Schmerzgrenze definiert. Wie im Video-Protokoll zeigte, Erfahrung C57BL / 6 Mäusen tiefe Allodynie so früh wie am ersten Tag nach der Operation und Pflege dieser für mehrere Wochen.

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

Die Verschont Nerve Injury Tiermodell wird hier als ein Maus-Modell von peripheren neuropathischen Schmerzen nach einer partiellen Denervation der Ischiasnerv durch Läsion der Tibia-und N. peronaeus Filialen beschrieben, so dass die verbleibenden Nervus suralis intakt. Verhaltensmodifikation durch mechanische Allodynie wird durch von Frey Filamente quantifiziert.

Die Verschont Nerve Injury (SNI) Modell induzierte mechanische Allodynie in Mäusen

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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JoVE Journal

Medicine

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

62.8K Aufrufe.  Aarhus University. Die Verschont Nerve Injury Tiermodell wird hier als ein Maus-Modell von peripheren neuropathischen Schmerzen nach einer partiellen Denervation der Ischiasnerv durch Läsion der Tibia-und N. peronaeus Filialen beschrieben, so dass die verbleibenden Nervus suralis intakt. Verhaltensmodifikation durch mechanische Allodynie wird durch von Frey Filamente quantifiziert.

Serie: 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.

Ein In vivo Nager-Modell der Kontraktion-induzierte Verletzung und nicht-invasive Überwachung von 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 ...

Forschung

Medizin

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.

Ischämie-Reperfusion-Modell des akuten Nierenschädigung und nach der Verletzung Fibrose bei Mäusen

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;

Tibialisnerv Durchtrennung - ein standardisiertes Modell für Denervation-induzierte Skelettmuskelatrophie in Mice

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.

Der Ischiasnerv cuffing Modell von neuropathischen Schmerzen bei Mäusen

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.

Facial Nerve Axotomie bei Mäusen: Ein Modell zur Motoneuron Reaktion auf eine Verletzung Studieren

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 induzierte fokale Ischämie als ein Modell der Rückenmarksverletzungen in Mäusen

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.

Ein Repetitive erschütternder Head Injury-Modell in Mäusen

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.

Induktion von beschleunigter Atherosklerose bei Mäusen: Das "Wire-Injury"-Modell

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.

Ein Tissue Displacement-basierte Contusive Spinal Cord Verletzung Modell in Mäusen

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.

Messung der isometrischen Kontraktilität der Maus mesenterialen Arterie mit Draht Myographie

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