Gli autori sono grati al Dr. N. Banik e Dr. D. Mitchell per la loro guida nello sviluppo di questo modello.

1. Preparazione Prima di lesioni del midollo spinale Gli strumenti chirurgici necessari per questa procedura sono bisturi, pickup con e senza denti, emostatiche, divaricatori auto di sostegno, multa rongeurs punta, driver aghi, suture riassorbibili, e la pelle applicatori di clip. Altre forniture chirurgiche necessarie sono teli chirurgici, lenzuola sterili per campo operatorio, spugne garza, applicatori di cotone-tip e lamina metallica. Autoclave gli strumenti chirurgici e le forniture prima della chirurgia. Utilizzare il set individuale di strumenti e forniture per un animale. Pulire l&#39;area chirurgica e apparecchi (simulazione, fonte di luce, cornice stereotassica, perle di vetro sterilizzatori, e rilievi di riscaldamento) con cotone imbevuto di alcol. Aprire i teli chirurgici e usare guanti sterili per coprire il campo chirurgico evitando accuratamente la contaminazione. Aprire i singoli strumenti sterilmente e posizionare con cura quelli nel campo chirurgico. Coprire le manopole e maniglie di secoloApparecchi e probabilmente necessario durante la procedura con la lamina metallica sterile. Accensione sulla sferetta sterilizzatore vetro per essere pronti per l&#39;uso durante la procedura. 2. Preparazione degli animali Portare i ratti alla zona laboratorio poche ore prima della procedura reale. Somministrare farmaci antidolorifici almeno un ora prima della procedura prevista (tipicamente buprinorphine 1,5 ml di 0,006 mg / ml per via sottocutanea). Somministrare antibiotici preoperatori (tipicamente Baytril 4 mg / kg per via sottocutanea). Anestetizzare i topi con 90 mg / kg di ketamina e aspettare fino a quando non vi è alcuna risposta in punta pizzico. Palpare il processo spinoso più prominente nella spina dorsale toracica. Questo livello corrisponde in genere con T10 processo spinoso. Segnare la posizione del livello previsto in relazione al T10. Nel nostro laboratorio eseguiamo una lesione T10. La narrazione segue descrive la tecnica del T10 SCI. Shave un cm x 6 cm rettangolo di 3 longitudinalmente e centrata a livello T10. Pulire la pelle tre volte wisoluzione di Betadine esimo. Applicare oftalmica lubrificante su ogni occhio. Trasferire il ratto in una posizione comoda per il campo chirurgico evitando accuratamente contaminazioni. Inserire una sonda di temperatura rettale per monitorare la temperatura interna e regolare il riscaldamento di conseguenza per mantenere la temperatura animale come vicino al normale (~ 37,5 ° C) come possibile. Coprire il ratto con un telo chirurgico con una finestra sopra il sito chirurgico. 3. Procedura chirurgica Inizia con un approssimativo 4 centimetri incisione con una lama di 10 ° centrato sul marchio T10. Procedere a sezionare con pazienza fascia e strati muscolari lontano dalle T9-T11 processi spinosi e lamine. Posizionare divaricatori per ritrarre muscolo e fascia dall&#39;osso. Mentre la stabilizzazione del processo spinoso di T9 nettamente dividere il legamento interspinoso tra T9 e T10 con le forbici sottili. Allo stesso modo stabilizzare il processo spinoso T10 e dividere il legamento interspinoso tra T10-T11. Utilizzare ingrandimento loop per complete la divisione dei legamenti tutto il percorso attraverso il legamento giallo (Figura 1). Il sacco durale è evidente una volta che il legamento giallo è scollegato. Utilizzare multa rongeurs punta per eseguire attentamente spicciolata laminectomia bilaterale a T10. Massima attenzione è presa per evitare una pressione al ribasso sul sacco durale e lesioni involontarie dalle punte rongeur. La lamina e il processo spinoso di T10 viene completamente rimosso. Spostare l&#39;animale in posizione sulla piattaforma di stabilizzazione. Utilizzare fascette stabilizzanti per immobilizzare la colonna vertebrale fissando gli aspetti laterali del corpo vertebrale T11 seguiti dagli aspetti laterali del corpo vertebrale T9. Fare attenzione a non comprimere il topo nella piattaforma con i morsetti di stabilizzazione poiché ciò limiterebbe lo spazio per i movimenti respiratori e aggiungere stress indesiderati l&#39;animale. Dopo aver fissato le impostazioni della colonna vertebrale sul dispositivo di simulazione computerizzato vengono controllati. Usiamo tipicamente punta d&#39;urto di 3,0 mm alla speed di 4 cm / s con una profondità di 2 mm ed un tempo di permanenza di 0,3 sec. Estendere la punta del pendolo e abbassarlo fino a che raggiunge la superficie del cavo. Ritrarre la punta e abbassare il dispositivo di due millimetri verso la superficie del midollo spinale. Rilasciare pistone dopo 4 cm / sec a causare gravi lesioni del midollo spinale contusione. Raggiungere emostasi utilizzando solo una pressione sufficiente a mantenere l&#39;applicatore cotone-tip a posto, facendo attenzione a non creare alcuna pressione eccessiva sul cavo. Sutura muscolare e strati fascia con una figura-8 punti facendo attenzione a non tirare il troppo stretto con suture assorbibili. Chiudere la pelle con un minimo di 2 piccoli punti metallici, fino a 4 o 5 punti metallici possono essere utilizzati se le parti della incisione rimangono aperti dopo le prime 2 o 3 punti. 3. -Procedura di cure post Luogo topi in un ambiente caldo di circa 33-35 ° C per 24 ore dopo l&#39;intervento. Ciò comporta un incubatore (mentre sono inconsci) e uno spazio gabbia riscaldata una volta che iniziano a muoversi. Una volta che i ratti sono completamente awake, somministrare 5 ml di soluzione fisiologica, 1,5 ml (0.006 mg / ml) di buprinorphine, e 0,1 ml di Baytril tutti per via sottocutanea. Continuare con buprinorphine per via sottocutanea due volte al giorno per le prime 24-48 ore e Baytril una volta al giorno per 7 giorni. Vesciche dovrebbero essere espressi manualmente tre volte al giorno fino al ritorno della funzione vescicale (&lt;2 ml di urina in espressione di mattina presto per 3 giorni consecutivi). Gli animali devono essere controllati in questo periodo per l&#39;infezione (sangue nelle urine, di colore biancastro, o cattivo odore), ridotta attività fisica o di problemi con la guarigione della ferita. Presenza di infezione deve essere contrastata con un aumento del dosaggio (o ri-avvio) di antibiotici, in consultazione con i veterinari locali. Pesare i ratti cominciano quotidiano il giorno dopo l&#39;intervento per valutare il loro recupero.

<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>

Informativa finanziaria nessuno Finanziamento divulgazione nessuno.

Diversi nuovi trattamenti hanno recentemente mostrato risultati promettenti inizi nel campo della ricerca sulle lesioni spinali. 3 valutazione attenta di questi trattamenti è indispensabile clinicamente rilevante modello di SCI per selezionare le strategie con il massimo potenziale traslazionale. Uno schema di classificazione è stato recentemente sviluppato per valutare la forza di studi preclinici. 9 Questo schema ha sottolineato l&#39;importanza di utilizzare modello contusione grave SCI. Qui s...

Scelta di un adeguato modello di lesione è cruciale per la valutazione preclinica di nuovi trattamenti per le lesioni del midollo spinale (SCI). 1,2,13 In una recente indagine di medici e scienziati nel campo del modello contusione neurotrauma, al contrario di emisezione o modelli completi transection , è stato universalmente accettato di essere clinicamente rilevante. 8 Il presente parere si basa sulla constatazione che la maggior parte delle lesioni del midollo spinale nell&#39;uomo è contusivo in natura. 10 La biologia della contusione sembra anche essere diverso da emisezione o transection modelli. Iseda 11, et al. confrontato l&#39;effetto di intraspinal condroitinasi iniezione ABC il neuroregeneration separatamente nei modelli contusione emisezione e. 4 rigenerazione assonale è stato osservato nel ponte neuronale in emisezione ma non il gruppo SCI contusione. Il modelli completi transection emisezione o anche creare le condizioni noti presenti in solo un piccolo sottoinsieme di clcircostanze inical. Ad esempio, diversi ricercatori hanno impiegato interventi impalcatura a base per l&#39;impianto nella cavità della lesione dopo emisezione o resezione completa per promuovere la rigenerazione. 6 Questo approccio diventa clinicamente irrilevante, perché la creazione di una cavità all&#39;interno midollo spinale danneggiato è impraticabile e probabilmente immorale. Variabilità nel recupero funzionale rimane una sfida importante per i modelli contusione. 5,12 Questa variabilità può essere minimizzato con l&#39;uso di urto e di stabilizzazione della colonna vertebrale computer controllati prima dell&#39;impatto per la consegna vigore uniforme in tutto il volume del midollo spinale in particolare le vie motorie situati ventralmente . Si deve notare che la plasticità e il contributo collaterale da assoni sopravvissuti è il meccanismo predominante di recupero dopo la lesione del midollo spinale. 1 variazioni Quindi anche minori in tecnica contusione possono produrre risultati molto diversi. A tal fine abbiamo sviluppatoun modello di gravi lesioni del midollo spinale da cui si ricava il volume contusione coerenti e recupero funzionale comparabile con i modelli transection. Questo modello può essere utilizzato per lo studio sia per la neuroprotezione e strategie neuroregeneration come prova di concetto per l&#39;efficacia del trattamento.

<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

Il potenziale traslazionale di nuovi trattamenti deve essere esaminata a gravi lesioni del midollo spinale (SCI) modelli contusione. Una metodologia dettagliata è descritta di ottenere un modello consistente di grave SCI. Uso di un telaio stereotassico e simulazione controllato da computer consente la creazione di lesioni riproducibile. Ipotermia e infezioni delle vie urinarie rappresentano sfide significative nel periodo post-operatorio. Un attento monitoraggio di animali con la registrazione del peso giornaliero e di espressione della vescica permette per la diagnosi precoce delle complicanze post-operatorie. I risultati funzionali di questo modello contusione sono equivalenti ai modelli transection. Il modello contusione può essere utilizzata per valutare l&#39;efficacia di entrambi gli approcci neuroprotettivi e neurorigenerativo.

Lesione del volume Abbiamo ottenuto grandi volumi e coerente lesioni mediante seguendo la tecnica descritta sopra. Utilizzando un Luxol veloce colorazione blu un volume delle lesioni media di 2,04 mm 3 (95% CI 1,9-2,18) (n = 5 animali) è stato ottenuto. Figura 2 mostra significa volume della lesione con una colorazione rappresentante utilizzando Luxol blu veloce attraverso l&#39;epicentro della lesione. Funzionali punteggi <p class="jov...

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

Un modello contusione di gravi lesioni del midollo spinale è descritto. Fasi di pre-operatoria, operatoria e post-operatoria dettagliate sono descritte di ottenere un modello coerente.

Un modello Contusione di gravi lesioni del midollo spinale nei ratti

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 Views.  Medical University of South Carolina. Un modello contusione di gravi lesioni del midollo spinale è descritto. Fasi di pre-operatoria, operatoria e post-operatoria dettagliate sono descritte di ottenere un modello coerente.

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.

Acuta e Cronica test sensoriale tattile dopo lesione del midollo spinale in ratti

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

Ricerca

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 modello contusivo unilaterale di lesioni del midollo spinale cervicale Uso della Impactor 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 modello murino di cervicale lesioni del midollo spinale per studiare post-lesionale respiratoria neuroplasticità

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.

Controllata corticale modello Impact per trauma cranico

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 radio-telemetria per monitorare la funzionalità cardiovascolare in ratti con midollo spinale e Transection embrionali staminali neurali Innesti cellulari

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 in Sperimentale Contusivi 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.

Calibrato forcipe Modello di Spinal Cord Injury 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.

Ultrasuoni Imaging per la valutazione di Spinal Cord Blood Flow in Sperimentale midollo spinale Lesioni

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-indotta ischemia focale come un modello di lesioni del midollo spinale nei topi

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 neonatale mouse Spinal Cord Injury compressione Modello

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