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

Todos los procedimientos ejecutados son aprobados por la Escuela de Medicina Institucional Cuidado de Animales y el empleo Comisión de la Universidad de Indiana y siguen Instituto Nacional de Salud directrices. 1. Técnica quirúrgica <ol><li> Mantenga una técnica aséptica durante este procedimiento mediante el uso de guantes estériles, instrumentos, y un campo quirúrgico estéril de acuerdo con las directrices del NIH 25. Esterilizar las herramientas antes de comenzar la cirugía mediante autoclave (véase la Tabla de específico Reactivos / Equipo para la lista completa). Utilice un esterilizador de perlas de vidrio para esterilizar las herramientas durante la operación. </li></ol> 2. Anestesia y Preparación <ol><li> Anestesiar al ratón en una caja de la anestesia con una mezcla de 0,9 L / min de oxígeno y 2,5% de isoflurano usando un sistema de vaporizador de isoflurano veterinaria. Asegúrese de que el ratón no responde a los cambios en la posición del cuerpo antes de sacarlo de la caja. </li><li> Aplicar pomada oftálmica al mouLos ojos de sí para protegerlos de la desecación. </li><li> Cambie el flujo de gas de la caja para el cono de la nariz. Coloque el ratón en ángulo recto en su lado izquierdo en una almohadilla de cubierta climatizada con una almohadilla quirúrgica y papel absorbente banco con su nariz y la boca en el interior del cono. Monitorear continuamente el ritmo respiratorio del ratón y la velocidad y ajustar los niveles de isoflurano según sea necesario (entre 2,5-3% isoflurano) para mantener un nivel adecuado de anestesia, y usar el pellizco reflejo dedo para confirmar la sedación total. </li></ol> 3. Abordaje quirúrgico <ol><li> Alinear y centrar el estereoscopio con el campo quirúrgico. Ajuste el cono de la nariz y la cinta hacia abajo para que se coloca a lo largo del borde del campo visual. </li><li> Con el ratón acostado en su lado izquierdo, con cinta adhesiva el borde de la oreja derecha al cono de nariz, la exposición del área detrás de la oreja donde se realizará la incisión. Asegúrese de que la vena auricular posterior se desplaza horizontalmente a través de la oreja. Tenga en cuenta que la colocación correcta de tque los animales y la grabación de la oreja son cruciales para encontrar rápidamente el nervio facial. </li><li> Humedezca la piel en y detrás de la oreja con etanol al 70% y afeitar el sitio quirúrgico utilizando una hoja de afeitar o bisturí. Pre-humedecer la piel hace que el afeitado más fácil en esta localización anatómica. </li><li> Limpiar la piel con una solución de yodo, tales como lavado quirúrgico Betadine (7,5% de povidona-yodo), seguido por etanol al 70%. Repita esta limpieza dos veces más para desinfectar a fondo el área. </li><li> Para determinar dónde hacer la incisión, traza la vena auricular posterior de la oreja caudalmente a la zona posterior a la protuberancia oído. Usando tijeras de primavera, hacer una incisión de 4 mm 2 - 3 mm posterior a la protuberancia. </li><li> Diseccionar a través de la grasa subcutánea y la máscara con disección roma. Evite el corte directo con las tijeras porque los vasos sanguíneos o tejido muscular podrían dañarse fácilmente. </li><li> Si se produce sangrado, aplique presión en el sitio de la cirugía con un hisopo de algodón estérildurante al menos 30 seg. Si se produce la pérdida de fluido significativa, inyectar el ratón por vía intraperitoneal con hasta 0,5 ml de solución salina al 0,9% estéril usando una aguja G 25 o 27. </li><li> Utilice varios hitos clave, el nervio espinal accesorio, canal auditivo, y anterior del músculo digástrico (descrito más adelante), para localizar el nervio facial. Diseccionar alrededor de estos puntos de referencia hasta que se visualizan las ramas del nervio facial. El nervio aparecerá como una estructura de sólido blanco significativa cuando se revela y una capa de fascia se adhiere a las estructuras subyacentes. <ol><li> Encuentra el nervio espinal accesorio, que viaja de la porción caudal del cráneo para inervar el músculo trapecio, una vez que la grasa subcutánea y la fascia se han diseccionado. El nervio facial es profundo en el nervio espinal accesorio. </li><li> Encuentra el conducto auditivo cartilaginoso que se ve de color blanco nacarado y se puede ver rostral al nervio facial. </li><li> Encontrar el vientre muscular del músculo digástrico anterior que se encuentra en la parte superior de y caudal al nervio facial. </li></ol></li><li> Cuando se visualizan las principales ramas del nervio facial, rastrearlos dorsal para encontrar su origen en el agujero estilomastoideo. Utilizando pinzas de punta fina Dumont # 5/45 para mantener el lugar de la cirugía abierta, avanzar en las puntas de las tijeras de primavera siguientes trayectoria del nervio, a continuación, mueva las pinzas dorsal para mantener el área recién abierta avanzada. </li><li> Visualice el tronco del nervio facial con el cigomático, bucal, y las ramas mandibulares marginales en este punto. NOTA: La rama temporal se encontrará más cerca del agujero. Las ramas del nervio mandibular marginal en sus partes superior e inferior más cerca de la mandíbula, por lo tanto aquellas ramas nerviosas no serán visibles en este nivel. <ol><li> Si se realiza un corte transversal del nervio, estabilizar el nervio suavemente con las pinzas de punta fina y cortar el nervio con las tijeras de primavera. Evite aplicar demasiada tracción en el nervio con las pinzas para evitar avulsing el nervio del tronco cerebral. Empujarlos tocones de distancia el uno del otro, o cortar y eliminar una porción del nervio distal para asegurar que no se produzca ninguna reconexión. </li><li> Si la realización de una lesión por aplastamiento, utilice Dumont # 5/45 pinzas para comprimir el nervio durante 30 segundos usando una presión constante para cortar todos los axones, repita este flechazo en un segundo ángulo perpendicular al primer sitio de aplastamiento. Evite aplicar cantidades variables de presión durante la aglomeración 30 segundos, de lo contrario el daño será inconsistente entre los animales. </li></ol></li></ol> 4. Cierre y Recuperación <ol><li> Vuelva a colocar la grasa y los músculos de las estructuras subyacentes. </li><li> Aproximar los bordes de la incisión y cerrar la herida usando un clip herida 7,5 mm. Las suturas o pegamento también son aceptables para el cierre de la herida. Analgésicos posquirúrgicas se pueden proporcionar en este momento. </li><li> Retire la cinta de la oreja del ratón. Apague el flujo isoflurano y permitir que el ratón para respirar oxígeno puro durante 30 segundos a 1 minuto. Place el ratón en una jaula vacía, sin ropa de cama para recuperarse de la anestesia. </li><li> Cuando se recupera el ratón, examine su comportamiento en busca de signos de confirmación de la parálisis facial. Los bigotes se paralizaron y en ángulo hacia la mejilla, la nariz se produce una desviación, y el ojo no parpadeará en respuesta a un soplo de aire. </li><li> Animales Casa en conjunto después de la cirugía si son de sexo femenino. Evite de ratones machos de forma conjunta, ya que son más agresivos y tienden a retirar por la fuerza clips de la herida de su cagemate, lo cual lleva a la infección. Proporcionar analgésicos posquirúrgicas en este momento, si es necesario. </li><li> Monitorear los ratones una vez al día durante varios días después de la operación para asegurarse de que no hay infección u otra complicación se produce después de la operación. Retire los clips de la herida 7-10 días después de la cirugía si no han caído por su propia cuenta. </li><li> Aplicar lubricante pomada ocular al ojo afectado diariamente para prevenir complicaciones de la córnea, o bien hasta que el reflejo del parpadeo del ojo es recubierta o hasta la eutanasia. </li></ol>

<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...

Existen muchos modelos de lesión del nervio periférico, pero uno que se destaca por el estudio de las motoneuronas es el modelo de axotomía del nervio facial. El nervio facial, también conocido como nervio craneal VII, se origina en la protuberancia y inerva los músculos de la expresión facial 1,2. En este protocolo quirúrgico, el nervio facial está expuesto en su salida del foramen estilomastoideo y ya sea corta o se tritura. La gravedad de la lesión del nervio puede clasificarse siguiendo las Sunderland 3 clasificaciones, que diferencia el daño basada en la integridad de los axones, endoneuro, perineuro y epineurio, que son capas de tejido conectivo que secuencialmente se envuelven alrededor de los haces de axones. En la lesión por aplastamiento (axonotmesis), los axones se cortan, pero el perineuro y epineurio se conservan. Recuperación funcional completa de aplastamiento del nervio facial se produce en alrededor de 11 días debido a que la vaina del nervio intacto sirve como un conducto en el que los axones vuelven a crecer 4,5. Porotro lado, en la lesión de corte (neurotmesis), los axones y las 3 capas de tejido conectivo se separó, y todo el nervio distal debe volver a crecer para restaurar la inervación musculatura. Reconexión quirúrgica de la epineurio se realiza a menudo en pacientes humanos con lesiones de la transección del nervio, sin embargo los resultados de la recuperación rara vez son óptimas. Se requieren más estudios para comprender por qué el nervio no puede volver a crecer a su objetivo y qué terapias se puede emplear para mejorar y acelerar el proceso de regeneración. Hay muchas ventajas para el estudio de la lesión del nervio utilizando el modelo de axotomía del nervio facial. En primer lugar, el procedimiento axotomía del nervio facial es rápido, fácil y altamente reproducible; y la parálisis resultante de los músculos faciales no afecta a las funciones vitales y es bien tolerado por el animal. Debido a que este es un modelo de lesión del nervio craneal, el estudio de los cuerpos celulares de las neuronas motoras se simplifica porque las motoneuronas residen en una población relativamente homogénea en ªe núcleo motor facial en la protuberancia. La población se diferencia en base al patrón subnuclear dentro del núcleo motor facial, ya que hay siete subnúcleos cada uno específico para que inervan un grupo específico de músculos, por lo que las diferencias subnucleares en respuesta a axotomía puede afectar los resultados de 2,6,7. Una ventaja importante del modelo de lesión del nervio facial es que el lado unaxotomized puede servir como un control interno emparejado porque la inervación del nervio es altamente simétrica y no hay diafonía entre los núcleos motores faciales 8. Otra ventaja de utilizar este método quirúrgico es la falta de un traumatismo directo al SNC o la interrupción de la barrera hematoencefálica 9. Las complicaciones como sangrado excesivo y la infección son raros con este procedimiento. Una variedad de análisis se puede realizar para evaluar la respuesta fisiológica a la lesión del nervio. La recuperación del reflejo del parpadeo del ojo y la actividad de la barba se puede utilizar como un comportamientomedida de 10,11 recuperación funcional. La grabación de vídeo de la actividad vibrisas es actualmente el método más poderoso para la detección de la recuperación de la inervación del nervio facial 12,13. Después de la eutanasia, el análisis histológico del tronco cerebral se puede realizar en los cuerpos celulares de las neuronas motoras en el núcleo motor facial. El núcleo motor facial se subdivide en siete subnúcleos, cada uno específico para ciertos músculos faciales, lo que permite el examen diferencial de las respuestas a la lesión 2,6. Las motoneuronas faciales pueden ser contados para cuantificar la supervivencia celular, o inmunohistoquímica pueden utilizarse para identificar biomarcadores y poblaciones de células específicas 14. El núcleo motor facial se puede microdissected con precisión utilizando captura por láser para el análisis molecular de la respuesta celular a la lesión del nervio 15,16. Impactos de la axotomía del nervio facial pueden ser analizados en la corteza motora 17,18. Además, el nervio puede ser diseccionado para estudiar la degeneración walleriana 19 oaxón de regeneración 20, y los músculos se pueden quitar para estudiar las uniones neuromusculares 21. La axotomía del nervio facial también puede ser utilizado para estudiar las células gliales centrales y periféricos que se acompañan 22, el objetivo de la musculatura 21, y el sistema inmune respuesta 23. Aunque se ha avanzado mucho en el estudio del modelo de axotomía del nervio facial 24, se requiere un mayor estudio de la lesión del nervio periférico, porque el daño nervioso es un problema importante para los pacientes y los tratamientos actuales no producen resultados óptimos. Este modelo es una poderosa herramienta para el examen de la respuesta fisiológica a la lesión del nervio y el análisis de la efectividad de las terapias de regeneración del nervio.

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facial nerve axotomy in mice: a model to study motoneuron response to injury

El objetivo de este protocolo quirúrgico es exponer el nervio facial, que inerva la musculatura facial, a su salida del foramen estilomastoideo y cortado o aplastarlo para inducir la lesión del nervio periférico. Ventajas de esta cirugía son su simplicidad, alta reproducibilidad, y la falta de efecto en las funciones vitales o la movilidad de la parálisis facial posterior, lo que resulta en un resultado quirúrgico relativamente leve en comparación con otros modelos de lesión del nervio. Una ventaja importante de utilizar un modelo de lesión del nervio craneal es que las motoneuronas residen en una población relativamente homogénea en el núcleo motor facial en la protuberancia, simplificando el estudio de los cuerpos celulares de las motoneuronas. Debido a la naturaleza simétrica de la inervación del nervio facial y la falta de diafonía entre los núcleos motores faciales, la operación se puede realizar de manera unilateral con el lado unaxotomized que sirve como un control interno emparejado. Una variedad de análisis se puede realizar después de la operación de asnoss la respuesta fisiológica, los detalles de los cuales están más allá del alcance de este artículo. Por ejemplo, la recuperación de la función muscular puede servir como un marcador de comportamiento para la reinervación, o las motoneuronas puede ser cuantificado para medir la supervivencia celular. Además, las neuronas motoras se pueden capturar con precisión utilizando microdisección por láser para el análisis molecular. Debido a que la axotomía del nervio facial es mínimamente invasiva y bien tolerada, puede ser utilizado en una amplia variedad de ratones modificados genéticamente. Además, este modelo de la cirugía puede ser utilizado para analizar la eficacia de los tratamientos de lesión del nervio periférico. Lesión del nervio facial proporciona un medio para investigar no sólo las motoneuronas, sino también las respuestas del microambiente central y periférico glial, el sistema inmunológico, y la musculatura de destino. El modelo de lesión del nervio facial es un modelo de lesión de nervio periférico ampliamente aceptado que sirve como una poderosa herramienta para el estudio de la lesión del nervio y la regeneración.

Después de que se realiza el axotomía del nervio facial, pérdida de las neuronas motoras se produce como resultado de la lesión. La supervivencia de las neuronas motoras después de la lesión depende de muchas variables, como el género, la edad del animal en el momento de la cirugía, y el punto de tiempo en el cual se realizan los recuentos de neuronas motoras, y el Moran y Graeber opinión el 24 y Jinno y Yamada opinión 22 tanto resumir los datos de supervivencia de las neuronas motoras. P...

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.

Axotomía nervio facial en ratones: un modelo para estudiar las motoneuronas respuesta a la lesión

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 vistas.  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. 

Video: 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 presión de la ventilación controlada para inducir la lesión pulmonar aguda en ratones

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

Investigación

Medicina

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.

La lesión del nervio Salvados (SNI) Modelo de alodinia mecánica inducida en ratones

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 modelo murino de la médula espinal cervical Lesión en estudio post-lesional Respiratorio Neuroplasticidad

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.

Lesión crónica constricción del nervio infraorbitario de la Rata (Ion-CCI) para el Estudio del trigémino Dolor Neuropático

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.

Un modelo de lesión en la cabeza repetidos de conmoción en ratones

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.

Inducción de la Aterosclerosis Acelerada en Ratones: El Modelo de "Lesiones por Alambre"

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 modelo de lesión de la médula espinal contundente basado en el desplazamiento de tejidos en ratones

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.

Medición de la contractilidad isométrica de la arteria mesentérica de ratón con cable miografía

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 generación de fracturas femorales cerradas en ratones: un modelo para el estudio del hueso curativo

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.

Modelo mejorado de roedores de isquemia miocárdica y lesión por reperfusión

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