Los autores agradecen al Dr. N. Banik y el Dr. D. Mitchell por su orientación en el desarrollo de este modelo.

1. Preparación Antes de una Lesión de la Médula Espinal Los instrumentos quirúrgicos necesarios para este procedimiento son bisturí, pastillas con o sin dientes, hemostáticos, retractores de auto contención, gubias punta fina, conductor de agujas, suturas absorbibles y aplicadores del clip de piel. Otros suministros quirúrgicos requeridos son paños quirúrgicos, sábanas estériles para campo quirúrgico, esponjas de gasa, aplicadores con punta de algodón, y papel metálico. Esterilizar en autoclave los instrumentos quirúrgicos y suministros antes de la cirugía. Utilice el conjunto individual de instrumentos y suministros para un animal. Limpie el área de la cirugía y aparatos (impactador, fuente de luz, marco estereotáctico, grano de cristal esterilizadores y almohadillas térmicas) con toallitas con alcohol. Abra las cortinas quirúrgicas y el uso de guantes estériles para cubrir el campo quirúrgico evitando cuidadosamente contaminación. Abra los instrumentos individuales estéril y colocar cuidadosamente los del campo quirúrgico. Cubra los pomos y tiradores de thaparato de correo probable necesario durante el procedimiento con la lámina metálica estéril. Encender la perla esterilizador de vidrio para estar listo para su uso durante el procedimiento. 2. Preparación de los animales Llevar las ratas a la zona de laboratorio pocas horas antes de que el procedimiento real. Administrar medicamentos para el dolor, al menos, una hora antes del procedimiento previsto (normalmente buprinorphine 1,5 ml de 0,006 mg / ml por vía subcutánea). Administrar antibióticos preoperatorios (típicamente Baytril 4 mg / kg por vía subcutánea). Anestesie las ratas con 90 mg / kg de ketamina y esperar hasta que no haya respuesta toe-pinch. Se palpa la apófisis espinosa más prominente en la columna torácica. Este nivel se corresponde normalmente con T10 apófisis espinosa. Marque la ubicación del nivel previsto en relación con T10. En nuestro laboratorio realizamos una lesión en T10. El siguiente relato describe la técnica de T10 SCI. Afeitado a 3 cm x 6 cm rectángulo longitudinal y centrada a nivel de T10. Limpie la piel tres veces wisolución de Betadine th. Aplicar lubricante oftálmica en cada ojo. Transferir la rata en una posición cómoda para el campo quirúrgico evitando cuidadosamente la contaminación. Inserte una sonda de temperatura rectal para monitorear la temperatura del núcleo y ajustar en consecuencia el calentamiento para mantener la temperatura animales como cerca de lo normal (~ 37,5 ° C) como sea posible. Cubrir la rata con un paño quirúrgico con una ventana por encima de la zona quirúrgica. 3. Procedimiento quirúrgico Comience con un aproximado de 4 cm incisión utilizando una cuchilla # 10 centrado en la marca de T10. Proceda a diseccionar pacientemente fascia y capas musculares lejos de las T9-T11 apófisis espinosas y las láminas. Coloque retractores para retraer el músculo y la fascia lejos del hueso. Mientras que la estabilización de la apófisis espinosa de T9 fuertemente dividir el ligamento interespinoso entre T9 y T10 con unas tijeras finas. Del mismo modo estabilizar la apófisis espinosa T10 y dividir el ligamento interespinoso entre T10-T11. Utilice ampliación bucle para complementarte la división de los ligamentos de todo el camino a través del ligamento amarillo (Figura 1). El saco tecal es fácilmente evidente una vez que el ligamento amarillo se desconecta. Utilice gubia de punta fina para realizar cuidadosamente laminectomía fragmentario bilateral en T10. Se toma el máximo cuidado para evitar una presión a la baja sobre el saco tecal y lesión inadvertida de las puntas gubia. La lámina y apófisis espinosa de T10 se elimina por completo. Mueva el animal en su posición en la plataforma de estabilización. Use abrazaderas estabilizadores para inmovilizar la columna vertebral de sujeción por los aspectos laterales del cuerpo vertebral T11 seguido por los aspectos laterales del cuerpo vertebral T9. Tenga cuidado de no comprimir la rata en la plataforma con las abrazaderas estabilizadoras ya que esto limitaría el espacio para los movimientos respiratorios y añadir estrés no deseado del animal. Después de asegurar se comprueban la configuración de columna vertebral en el impactador controlado por ordenador. Normalmente usamos punta impactador de 3,0 mm a una speed de 4 cm / s, con una profundidad de 2 mm y un tiempo de permanencia de 0,3 segundos. Extienda la punta del péndulo y bajarlo hasta que toque la superficie dorsal. Retirar la punta y bajar el dispositivo de 2 mm hacia la superficie de la médula espinal. Suelte pistón en 4 cm / s para causar contusión lesión medular grave. Lograr la hemostasia utilizando sólo la presión suficiente para mantener el aplicador de punta de algodón en el lugar, teniendo cuidado de no crear una presión innecesaria sobre el cable. Sutura del músculo y las capas de la fascia con una sutura en forma de 8 con cuidado de no tirar de la muy apretada con suturas absorbibles. Cierre la piel con un mínimo de 2 pequeñas grapas, puede tener hasta 4 o 5 grapas pueden usarse si las partes de la incisión permanecen abiertos después de las primeras 2 o 3 grapas. 3. Cuidados después del procedimiento Ratas en un ambiente cálido de unos 33 a 35 ° C durante 24 horas después de la cirugía. Esto implica una incubadora (mientras están inconscientes) y un espacio de jaula climatizada, una vez que comienzan a moverse. Una vez que las ratas son completamente awome, administrar 5 ml de solución salina, 1,5 ml (0,006 mg / ml) de buprinorphine, y 0,1 ml de Baytril todo por vía subcutánea. Continúe con buprinorphine subcutánea dos veces al día para el primer 24-48 hy Baytril una vez al día durante 7 días. Las vejigas deben expresarse manualmente tres veces al día hasta el regreso de la función de la vejiga (&lt;2 ml de orina en la expresión temprano por la mañana durante 3 días consecutivos). Los animales también deben ser revisados ​​durante este tiempo de infección (sangre en la orina, color blanquecino o mal olor), disminución de la actividad física o los problemas con la cicatrización de la herida. La presencia de la infección debe ser contrarrestado con un aumento de la dosis (o reinicio) de antibióticos en consulta con los veterinarios locales. Pesar ratas comienzan diario el día después de la cirugía para evaluar su recuperación.

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V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+speed+does+not+determine+severity+of+spinal+cord+injury+in+mice+with+fixed+impact+displacement.">Impact speed does not determine severity of spinal cord injury in mice with fixed impact displacement.</a> Journal of Neurotrauma. 26, 1395-1404 (2009).</li><li>Kwon, B. K., Hillyer, J., Tetzlaff, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Translational+research+in+spinal+cord+injury:+a+survey+of+opinion+from+the+SCI+community.">Translational research in spinal cord injury: a survey of opinion from the SCI community.</a> J. Neurotrauma. 27, 21-33 (2010).</li><li>Kwon, B. K., Okon, E. 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No divulgación de información financiera Ninguna revelación financiación.

Varios nuevos tratamientos han demostrado recientemente promesa temprana en el campo de la investigación SCI. 3 La evaluación cuidadosa de estos tratamientos es esencial en el modelo clínicamente relevante de SCI para seleccionar estrategias con potencial de traslación máxima. Un esquema de clasificación fue desarrollado recientemente para evaluar la fuerza de los estudios preclínicos. 9 Este esquema hizo hincapié en la importancia de utilizar modelos contusión severa SCI. Aquí se describ...

Elección del modelo de lesión adecuada es fundamental para la evaluación preclínica de nuevos tratamientos para lesiones de la médula espinal (SCI). 1,2,13 En una reciente encuesta de los médicos y científicos en el campo de la modelo contusión neurotrauma, a diferencia de los modelos de transección completa hemisección o , fue universalmente aceptado para ser clínicamente relevante. 8 Esta opinión se basa en la observación de que la mayoría de las lesiones de la médula espinal en los seres humanos es contusa en la naturaleza. 10 La biología de contusión también parece ser diferente de los modelos de hemisección o transección. 11 Iseda, et al. comparó el efecto de la inyección intraespinal condroitinasa ABC en neuroregeneración por separado en los modelos de contusión y hemisección. 4 regeneración axonal se observó en el puente neuronal en hemisección pero no el grupo SCI contusión. Los modelos transección completa hemisección o también crean las condiciones conocidas en sólo un pequeño subconjunto de clcircunstancias inical. Por ejemplo, varios investigadores han empleado intervenciones andamio basados ​​para la implantación en la cavidad de la lesión después de la hemisección o transección completa para promover la regeneración. 6 Este enfoque se vuelve clínicamente irrelevantes porque la creación de una cavidad dentro de la médula espinal lesionada es poco práctico y probablemente no ética. La variabilidad en la recuperación funcional sigue siendo un desafío importante para los modelos de contusión. 5,12 Esta variabilidad puede ser minimizado mediante el uso de impactador controlado por ordenador y la estabilización de la columna vertebral antes del impacto para la entrega de fuerza uniforme en todo el volumen de la médula espinal en especial las vías motoras situadas ventralmente . Debe tenerse en cuenta que la plasticidad y la contribución garantía de axones supervivientes es el mecanismo predominante de la recuperación después de lesión de la médula espinal. 1 Por lo tanto, incluso variaciones menores en la técnica de contusión pueden producir resultados significativamente diferentes. Con este fin hemos desarrolladoun modelo de lesión medular severa que produce contusión volumen constante y la recuperación funcional comparable con los modelos de transección. Este modelo puede ser utilizado tanto para la investigación de la neuroprotección y estrategias Neuroregeneración como una prueba de concepto para la eficacia del tratamiento.

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

a contusion model of severe spinal cord injury in rats

El potencial de la traducción de nuevos tratamientos debe ser investigado en lesiones graves de la médula espinal (SCI) modelos contusión. Una metodología detallada se describe para obtener un modelo consistente de severa SCI. El uso de un marco estereotáctico y impactador controlado por ordenador permite la creación de lesión reproducible. La hipotermia y las infecciones del tracto urinario representan retos significativos en el período post-operatorio. Monitoreo cuidadoso de los animales con la grabación diaria de peso y la expresión de vejiga permite la detección precoz de las complicaciones post-operatorias. Los resultados funcionales de este modelo contusión son equivalentes a los modelos de transección. El modelo de contusión se puede utilizar para evaluar la eficacia de ambos enfoques neuroprotectores y neuroregenerativos.

Volumen de la lesión Hemos obtenido grandes volúmenes de la lesión y coherente siguiendo la técnica descrita anteriormente. El uso de un Luxol rápido tinción con azul de un volumen de la lesión media de 2,04 mm 3 (IC del 95% 01.09 hasta 02.18) (n = 5 animales) se obtuvo. Figura 2 muestra significa volumen de la lesión con una tinción representativa utilizando azul rápido Luxol a través de la lesión epicentro. Las puntuaciones fun...

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

A Contusion Model of Severe Spinal Cord Injury in Rats

Se describe un modelo de contusión de la lesión medular grave. Medidas pre-operatorio, operatorio y post-operatorio detalladas se describen para obtener un modelo coherente.

Un modelo Contusión de la lesión de la médula espinal severa en ratas

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

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

Research

JoVE Journal

Medicine

30.2K vistas.  Medical University of South Carolina. Se describe un modelo de contusión de la lesión medular grave. Medidas pre-operatorio, operatorio y post-operatorio detalladas se describen para obtener un modelo coherente.

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

Acute and Chronic Tactile Sensory Testing after Spinal Cord Injury in Rats

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory testing in rat SCI models is needed. However, until recently, no single testing approach had been validated for SCI so that standardized methods have not been implemented across labs. Additionally, available testing methods could not be implemented acutely or when severe motor impairments existed, preventing studies of the development of SCI-induced allodynia3. Here we present two validated sensory testing methods using von Frey Hair (VFH) monofilaments which quantify changes in tactile sensory thresholds after SCI4-5. One test is the well-established Up-Down test which demonstrates high sensitivity and specificity across different SCI severities when tested chronically5. The other test is a newly-developed dorsal VFH test that can be applied acutely after SCI when allodynia develops, prior to motor recovery4-5. Each VFH monofilament applies a calibrated force when touched to the skin of the hind paw until it bends. In the up-down method, alternating VFHs of higher or lower forces are used on the plantar L5 dermatome to delineate flexor withdrawal thresholds. Successively higher forces are applied until withdrawal occurs then lower force VFHs are used until withdrawal ceases. The tactile threshold reflects the force required to elicit withdrawal in 50% of the stimuli. For the new test, each VFH is applied to the dorsal L5 dermatome of the paw while the rat is supported by the examiner. The VFH stimulation occurs in ascending order of force until at least 2 of 3 applications at a given force produces paw withdrawal. Tactile sensory threshold is the lowest force to elicit withdrawal 66% of the time. Acclimation, testing and scoring procedures are described. Aberrant trials that require a retest and typical trials are defined. Animal use was approved by Ohio State University Animal Care and Use Committee.

We describe two tactile sensory testing methods for acute or chronic periods of spinal cord injury in rats. These validated procedures can detect the development and maintenance of allodynia-like sensations.

Aguda y crónica Prueba sensorial táctil después de la lesión de la médula espinal en ratas

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

Investigación

Medicina

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

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

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

Un modelo de la contundente unilateral Lesión Medular Cervical Uso del Impactador Infinite Horizon

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

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

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

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

Un 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 ...

Controlled Cortical Impact Model for Traumatic Brain Injury

Every year over a million Americans suffer a traumatic brain injury (TBI). Combined with the incidence of TBIs worldwide, the physical, emotional, social, and economical effects are staggering. Therefore, further research into the effects of TBI and effective treatments is necessary. The controlled cortical impact (CCI) model induces traumatic brain injuries ranging from mild to severe. This method uses a rigid impactor to deliver mechanical energy to an intact dura exposed following a craniectomy. Impact is made under precise parameters at a set velocity to achieve a pre-determined deformation depth. Although other TBI models, such as weight drop and fluid percussion, exist, CCI is more accurate, easier to control, and most importantly, produces traumatic brain injuries similar to those seen in humans. However, no TBI model is currently able to reproduce pathological changes identical to those seen in human patients. The CCI model allows investigation into the short-term and long-term effects of TBI, such as neuronal death, memory deficits, and cerebral edema, as well as potential therapeutic treatments for TBI.

Traumatic brain injuries (TBIs) remain a serious health problem. Using the controlled cortical impact surgery model, research on the effects of TBI and possible treatment methods may be performed.

Controlado Modelo de Impacto cortical de la lesión cerebral traumática

Every year over a million Americans suffer a traumatic brain injury (TBI).  Combined with the incidence of TBIs worldwide, the physical, emotional, ...

A Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter connected to a radio transmitter into the femoral artery of rats that underwent a T4 spinal cord transection with or without grafting of embryonic brainstem-derived neural stem cells expressing green fluorescent protein. Compared to other methods such as cannula insertion or tail-cuff, telemetry is advantageous to continuously monitor blood pressure and heart rate in freely moving animals. It is also capable of long term multiple data acquisitions. In spinal cord injured rats, basal cardiovascular data under unrestrained condition and autonomic dysreflexia in response to colorectal distension were successfully recorded. In addition, cardiovascular parameters before and after SCI can be compared in the same rat if a transmitter is implanted before a spinal cord transection. One limitation of the described telemetry procedure is that implantation in the femoral artery may influence the blood supply to the ipsilateral hindlimb.

We present a protocol for using a radio-telemetric system to record cardiovascular parameters in T4 spinal cord transected rats eight weeks after embryonic brainstem neural stem cell grafting into the lesion site. Telemetry is an advanced technique to accurately evaluate cardiovascular function in conscious freely moving spinal cord injured rats.

Un sistema de radio-telemetría para monitorizar la función cardiovascular en ratas con la médula espinal y transección Embryonic Stem Neural injertos de células

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

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

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

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

Neural Trasplante de células madre en Experimental contuso Modelo de Lesión de la Médula Espinal

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

Calibrated Forceps Model of Spinal Cord Compression Injury

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

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

Calibrado Pinzas Modelo de Lesión Medular Compresión

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

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

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

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

Contraste mejorado las imágenes por ultrasonido para la Evaluación de la Médula Espinal flujo sanguíneo en Experimental Spinal Cord Injury

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

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 inducida por isquemia focal como un modelo de lesión de médula espinal en ratones

Spinal cord injury (SCI) is a devastating clinical condition causing permanent changes in sensorimotor and autonomic functions of the spinal cord (SC) ...

A Neonatal Mouse Spinal Cord Compression Injury Model

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal cord. A major current area of research is focused on the mechanisms of adaptive plasticity that underlie spontaneous or induced functional recovery following SCI. Spontaneous functional recovery is reported to be greater early in life, raising interesting questions about how adaptive plasticity changes as the spinal cord develops. To facilitate investigation of this dynamic, we have developed a SCI model in the neonatal mouse. The model has relevance for pediatric SCI, which is too little studied. Because neural plasticity in the adult involves some of the same mechanisms as neural plasticity in early life1, this model may potentially have some relevance also for adult SCI. Here we describe the entire procedure for generating a reproducible spinal cord compression (SCC) injury in the neonatal mouse as early as postnatal (P) day 1. SCC is achieved by performing a laminectomy at a given spinal level (here described at thoracic levels 9-11) and then using a modified Yasargil aneurysm mini-clip to rapidly compress and decompress the spinal cord. As previously described, the injured neonatal mice can be tested for behavioral deficits or sacrificed for ex vivo physiological analysis of synaptic connectivity using electrophysiological and high-throughput optical recording techniques1. Earlier and ongoing studies using behavioral and physiological assessment have demonstrated a dramatic, acute impairment of hindlimb motility followed by a complete functional recovery within 2 weeks, and the first evidence of changes in functional circuitry at the level of identified descending synaptic connections1.

This article describes a method for generating a reproducible spinal cord compression injury (SCI) in the neonatal mouse. The model provides an advantageous platform for studying mechanisms of adaptive plasticity that underlie spontaneous functional recovery.

Un ratón neonatal lesión de médula espinal de compresión Modelo

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