Os autores agradecem ao Dr. N. Banik e Dr. D. Mitchell para a sua orientação no desenvolvimento deste modelo.

1. Preparação Antes de Lesão Medular Os instrumentos cirúrgicos necessários para este procedimento são bisturi, captadores com e sem dentes, hemostats, afastadores de auto-retenção, rongeurs de ponta fina, motorista agulha, suturas absorvíveis e clip aplicadores da pele. Outros suprimentos cirúrgicos necessários são campos cirúrgicos, lençóis estéreis para campo operatório, gaze esponjas, aplicadores de algodão-ponta, e folhas metálicas. Autoclave os instrumentos cirúrgicos e material antes da cirurgia. Use o conjunto individual de instrumentos e materiais para um animal. Limpe a área cirúrgica e aparelhos (pêndulo, fonte de luz, quadro estereotáxico, contas de vidro esterilizadores, e esquentadores), com algodão embebido em álcool. Abra as cortinas cirúrgicas e usar luvas estéreis para armar o campo cirúrgico cuidadosamente evitando a contaminação. Abra os instrumentos individuais esterilizada e coloque cuidadosamente as do campo cirúrgico. Cubra os botões e puxadores de thaparelhos e provavelmente necessário durante o procedimento, com a folha metálica estéril. Ligar o talão esterilizador de vidro para estar pronto para o uso durante o procedimento. 2. Preparação dos Animais Trazer os ratos para o laboratório algumas horas antes da área do procedimento real. Administrar medicação para a dor, pelo menos, uma hora antes do procedimento esperado (tipicamente buprinorphine 1,5 ml de 0,006 mg / ml por via subcutânea). Administrar antibióticos pré-operatórios (Baytril tipicamente de 4 mg / kg por via subcutânea). Anestesiar os ratos utilizando 90 mg / kg de cetamina e esperar até que não haja resposta toe-pitada. Palpar o processo espinhoso mais proeminente na coluna torácica. Este nível corresponde tipicamente com T10 processo espinhoso. Marque a localização do nível pretendido em relação a T10. Em nosso laboratório realizamos uma lesão T10. A narrativa seguinte descreve a técnica de T10 SCI. Shave a 3 centímetros x 6 cm rectângulo longitudinalmente e centrado em T10 nível. Limpe a pele três vezes wisolução Betadine ª. Aplique lubrificante oftálmico em cada olho. Transfira o rato em uma posição confortável para o campo cirúrgico cuidadosamente evitando a contaminação. Insira uma sonda rectal de temperatura para monitorizar a temperatura do núcleo e ajustar o aquecimento em conformidade para manter a temperatura do animal mais próximo do normal (~ 37,5 ° C), como possível. Cobrir o rato com uma cobertura cirúrgica com uma janela sobre o local cirúrgico. 3. Procedimento Cirúrgico Comece com uma incisão de aproximadamente 4 centímetros usando uma lâmina # 10 centrada na marca T10. Proceder de dissecar pacientemente fáscia e camadas musculares longe das T9-T11 processos espinhosos e lâminas. Coloque afastadores para retrair o músculo e fáscia longe do osso. Enquanto a estabilização do processo espinhoso de T9 acentuadamente dividir o ligamento interespinhoso entre T9 e T10 usando uma tesoura fina. Da mesma forma a estabilizar o processo espinhoso T10 e dividir o ligamento interespinhoso entre T10-T11. Use ampliação loop para complete a divisão dos ligamentos todo o caminho através do ligamento amarelo (Figura 1). O saco tecal é facilmente perceptível uma vez que o ligamento amarelo é desconectada. Use fórceps de ponta fina para realizar cuidadosamente peça-refeição laminectomia bilateral em T10. O máximo de cuidado é tomado para evitar a pressão sobre o saco tecal e ferimento acidental com as pontas rongeur. A lâmina e processo espinhoso de T10 é completamente removido. Coloque o animal em posição na plataforma de estabilização. Use grampos estabilizantes para imobilizar a coluna por aperto as faces laterais do corpo vertebral T11 seguido pelas faces laterais do corpo vertebral T9. Tenha cuidado para não comprimir o rato na plataforma com os grampos de estabilização, pois isso seria restringir o espaço para os movimentos respiratórios e adicione estresse indesejado do animal. Depois de garantir os ajustes da coluna vertebral no pêndulo controlado por computador são verificados. Normalmente usamos ponta pêndulo de 3,0 mm a uma speed de 4 cm / s, com uma profundidade de 2 mm e um tempo de permanência de 0,3 segundos. Estenda a ponta do pêndulo eo abaixá-lo até tocar a superfície do fio. Retrair a ponta e diminuir o dispositivo de 2 milímetros em direção à superfície da medula espinhal. Solte pistão a 4 cm / seg para causar grave contusão lesão medular. Atingir hemostasia utilizando apenas pressão suficiente para manter o aplicador com ponta de algodão no lugar, tomando cuidado para não criar qualquer pressão desnecessária sobre o cabo. Sutura muscular e camadas de fáscia com uma figura-8 ponto tomando cuidado para não puxar o muito apertado com suturas absorvíveis. Fechar a pele com um mínimo de dois pequenos grampos, até 4 ou 5 grampos podem ser utilizados, se as partes da incisão permanecer aberto após os primeiros dois ou três grampos. 3. Cuidados pós-procedimento Ratos num ambiente quente de cerca de 33-35 ° C por 24 horas pós-cirurgia. Isto implica uma incubadora (enquanto eles são inconscientes) e um espaço gaiola aquecida, uma vez que eles começam a se mover. Uma vez que os ratos são totalmente awake, administrar 5 ml de soro fisiológico, 1,5 ml (0,006 mg / ml) de buprinorphine, e 0,1 ml de Baytril todos subcutaneamente. Continue com buprinorphine por via subcutânea duas vezes por dia para o primeiro 24-48 hr e Baytril uma vez por dia durante 7 dias. As bexigas deve ser ordenhado, três vezes por dia até o retorno da função de bexiga (&lt;2 ml de urina na expressão de manhã cedo, durante 3 dias consecutivos). Os animais também deve ser verificado durante este tempo de infecção (sangue na urina, cor esbranquiçada, ou um odor desagradável), diminuição da atividade física ou problemas de cicatrização. Presença de infecção deve ser combatida com o aumento da dose (ou reinício) de antibióticos em consulta com veterinários locais. Pesar ratos diariamente a partir do dia após a cirurgia para avaliar a sua recuperação.

<ol>
	<li>Blesch, A., Tuszynski, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+injury:+plasticity,+regeneration+and+the+challenge+of+translational+drug+development.">Spinal cord injury: plasticity, regeneration and the challenge of translational drug development.</a> Trends Neurosci. 32, 41-47 (2009).</li><li>Dobkin, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Curiosity+and+cure:+translational+research+strategies+for+neural+repair-mediated+rehabilitation.">Curiosity and cure: translational research strategies for neural repair-mediated rehabilitation.</a> Dev. Neurobiol. 67, 1133-1147 (2007).</li><li>Fehlings, M. G., Cadotte, D. W., Fehlings, L. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+series+of+systematic+reviews+on+the+treatment+of+acute+spinal+cord+injury:+a+foundation+for+best+medical+practice.">A series of systematic reviews on the treatment of acute spinal cord injury: a foundation for best medical practice.</a> J. Neurotrauma. 28, 1329-1333 (2011).</li><li>Iseda, T., Okuda, T., Kane-Goldsmith, N., 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=Single,+high-dose+intraspinal+injection+of+chondroitinase+reduces+glycosaminoglycans+in+injured+spinal+cord+and+promotes+corticospinal+axonal+regrowth+after+hemisection+but+not+contusion.">Single, high-dose intraspinal injection of chondroitinase reduces glycosaminoglycans in injured spinal cord and promotes corticospinal axonal regrowth after hemisection but not contusion.</a> J. Neurotrauma. 25, 334-349 (2008).</li><li>Khan, T., Havey, R. M., Sayers, S. T., 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=Animal+models+of+spinal+cord+contusion+injuries.">Animal models of spinal cord contusion injuries.</a> Laboratory Animal Science. 49, 161-172 (1999).</li><li>Kim, B. G., Kang, Y. M., Phi, J. H., 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=Implantation+of+polymer+scaffolds+seeded+with+neural+stem+cells+in+a+canine+spinal+cord+injury+model.">Implantation of polymer scaffolds seeded with neural stem cells in a canine spinal cord injury model.</a> Cytotherapy. 12, 841-845 (2010).</li><li>Kim, J. H., Tu, T. W., Bayly, P. 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. B., Tsai, E., 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=A+grading+system+to+evaluate+objectively+the+strength+of+pre-clinical+data+of+acute+neuroprotective+therapies+for+clinical+translation+in+spinal+cord+injury.">A grading system to evaluate objectively the strength of pre-clinical data of acute neuroprotective therapies for clinical translation in spinal cord injury.</a> J. Neurotrauma. 28, 1525-1543 (2011).</li><li>Norenberg, M. D., Smith, J., Marcillo, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+pathology+of+human+spinal+cord+injury:+defining+the+problems.">The pathology of human spinal cord injury: defining the problems.</a> J. Neurotrauma. 21, 429-440 (2004).</li><li>Siegenthaler, M. M., Tu, M. K., Keirstead, H. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+extent+of+myelin+pathology+differs+following+contusion+and+transection+spinal+cord+injury.">The extent of myelin pathology differs following contusion and transection spinal cord injury.</a> J. Neurotrauma. 24, 1631-1646 (2007).</li><li>Talac, R., Friedman, J. A., Moore, M. J., 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=Animal+models+of+spinal+cord+injury+for+evaluation+of+tissue+engineering+treatment+strategies.">Animal models of spinal cord injury for evaluation of tissue engineering treatment strategies.</a> Biomaterials. 25, 1505-1510 (2004).</li><li>Tator, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+treatment+trials+in+human+spinal+cord+injury:+issues,+difficulties,+and+recommendations.">Review of treatment trials in human spinal cord injury: issues, difficulties, and recommendations.</a> Neurosurgery. 59, 957-982 (2006).</li></ol>

Nenhum divulgação financeira Nenhum divulgação financiamento.

Vários novos tratamentos têm mostrado recentemente promessa adiantada no campo de pesquisa SCI. 3 avaliação cuidadosa destes tratamentos é essencial no modelo clinicamente relevante da SCI para selecionar estratégias com potencial translacional máximo. Um esquema de classificação foi recentemente desenvolvido para avaliar a força de estudos pré-clínicos. 9 Este esquema enfatizou a importância da utilização do modelo de SCI contusão grave. Aqui nós descrevemos um modelo desse tipo d...

Escolha do modelo de lesão adequado é fundamental para a avaliação pré-clínica de novos tratamentos para a lesão da medula espinhal (SCI). 1,2,13 Em uma recente pesquisa de médicos e cientistas no domínio do modelo de contusão neurotrauma, ao contrário de hemisection ou modelos completos transecção , foi universalmente aceito para ser clinicamente relevante. 8 Esta opinião é baseada na observação de que a maioria da lesão medular em humanos é contundente na natureza. 10 A biologia de contusão também parece ser diferente dos modelos hemissecção ou transecção. Iseda 11, et ai. comparou o efeito de injecção intra-espinal condroitinase ABC no neuroregeneração separadamente em contusão hemisecção e modelos. quatro regeneração axonal foi observada na ponte neuronal em hemisecção mas não o grupo SCI contusão. O hemisection ou modelos completos transecção também criar condições conhecidas de existir em apenas um pequeno subconjunto de clcircunstâncias inical. Por exemplo, vários investigadores têm utilizado as intervenções baseadas em andaime para o implante na cavidade lesão após hemisection ou transecção completa para promover a regeneração. 6 Essa abordagem torna-se clinicamente irrelevante, porque a criação de uma cavidade dentro lesionado medular é impraticável e provavelmente antiético. Variabilidade na recuperação funcional continua a ser um grande desafio para os modelos de contusão. 5,12 Esta variabilidade pode ser minimizado pela utilização de pêndulo, controlado por computador e estabilização da coluna vertebral antes do impacto, para a entrega de força uniforme, através do volume da medula espinal nomeadamente as vias motoras ventralmente localizadas . Deve-se notar que a plasticidade ea contribuição garantia de sobreviventes axônios é o mecanismo predominante de recuperação após a lesão medular. 1 Portanto, mesmo pequenas variações na técnica de contusão pode produzir resultados significativamente diferentes. Para este fim, temos desenvolvidoum modelo de grave lesão da medula espinhal que produz volume de contusão consistente e recuperação funcional comparável com modelos transecção. Este modelo pode ser utilizado para investigar tanto a neuroproteção e estratégias neuroregeneração como uma prova de conceito para a eficácia do tratamento.

<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

O potencial translacional de novos tratamentos devem ser investigadas em lesão medular grave (SCI) modelos de contusão. A metodologia detalhada é descrita a obtenção de um modelo consistente de SCI grave. Utilização de uma moldura estereotáxica e computador pêndulo controlada permite a criação de lesão reprodutível. Hipotermia e infecção do trato urinário representam desafios significativos no período pós-operatório. Monitorização cuidadosa dos animais com registro de peso diário e expressão bexiga permite a detecção precoce de complicações pós-operatórias. Os resultados funcionais deste modelo de contusão são equivalentes aos modelos transecção. O modelo de contusão pode ser utilizado para avaliar a eficácia de ambas as abordagens neuroprotectores e neuroregenerative.

Volume lesão Obtivemos grandes volumes de lesão e consistente, seguindo a técnica acima descrita. Usando um Luxol rápida coloração de uma volume de lesão média de 2,04 mm 3 (IC 1,9-2,18 95%) (n = 5 animais) foi obtido azul. Figura 2 mostra a média do volume da lesão com uma coloração representativo usando Luxol azul rápido através do epicentro da lesão. Escores funcionais As pontuações de comport...

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

Um modelo de contusão grave lesão da medula espinhal é descrito. As etapas detalhadas no pré-operatório, operatório e pós-operatório são descritos para obter um modelo consistente.

Um modelo de contusão grave de lesão medular em ratos

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 visualizações.  Medical University of South Carolina. Um modelo de contusão grave lesão da medula espinhal é descrito. As etapas detalhadas no pré-operatório, operatório e pós-operatório são descritos para obter um modelo consistente.

Vídeo: 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 e crônica teste sensorial tátil após a lesão medular em ratos

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

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.

Um Modelo contundente de lesão da medula espinhal cervical unilateral Usando o Impactor horizonte infinito

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.

Um modelo murino de Spinal Cord Injury do colo do útero para o Estudo de pós-lesional respiratória Neuroplasticidade

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 Impact Cortical para lesão 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.

Um sistema de rádio-telemetria para monitorar a função cardiovascular em ratos com Medula Espinhal transecção e Embryonic Stem Neural enxertos 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 Stem Cell Transplantation em Experimental contusão 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 ...

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 Fórceps Modelo de Lesão Medular Compression

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 melhorado Ecografia de Avaliação da Medula Espinhal fluxo de sangue em Experimental lesão medular

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.

Fototrombose induzida por isquemia focal como um Modelo de Lesão Medular em Ratos

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.

A Neonatal do rato Spinal Cord Injury Compression Modelo

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