evaluation of injury contusion in mice for spinal injury analysis

Un dispositivo per la contusione della lesione del midollo spinale per modelli murini accurati

Spinal cord injury usually results in permanent spinal cord dysfunction below the injured segment. It is mostly caused by objects striking the spine and hyperextension of the spine, such as traffic accidents and falls1. Due to the limited availability of effective treatment options for spinal cord injury, elucidation of the pathogenesis of spinal cord injuries using animal models will be informative for the development of appropriate treatment approaches. The contusion model of spinal cord injury caused by impact on the spinal cord results in the development of animal models with similar pathologies to most clinical spinal cord injury cases2,3. Therefore, it is important to produce accurate, reproducible, and convenient animal models for spinal cord injury contusion.
Since Allen&#39;s invention of the first animal model of spinal cord injury in 1911, there have been major advances in the development of instruments for establishing spinal cord injury animal models4,5. Based on injury mechanisms, spinal cord injury models are classified as contusion, compression, distraction, dislocation, transection, or chemical6. Among them, the contusion models, which use external forces to displace and injure the spinal cord, are closest to the clinical etiology of most spinal cord injury patients. Therefore, the contusion model has been used by many investigators in spinal cord injury studies3,7. Various instruments are used to develop spinal cord injury contusion models. The New York University (NYU)-multicenter animal spinal cord injury studies (MASCIS) impactor produces spinal cord injury contusions by weight-drop device8. After several updated versions, the MASCIS impactor is widely used to develop spinal cord injury contusion animal models9. However, when the impact rod of MASCIS falls and hits the spinal cord, multiple injuries may occur, which affects the degree of injury in spinal cord injury models. Moreover, achieving mechanical precision to ensure the accuracy of the instrument and the repeatability of the manufacturing model is also challenging. The infinite horizon impactors cause contusions by controlling the force applied to the spinal cord rather than heavy drops10. It uses a computer connected to a sensor to directly measure the impact force between the impactor and the spinal cord. When the threshold is reached, the impactor is immediately retracted, thereby avoiding weight rebound and improving accuracy10,11. However, the use of this fine motor modality to inflict damage can result in inconsistent damage and functional deficits6. The Ohio State University (OSU) device compresses the dorsal surface of the spinal cord at a transient rate by an electromagnetic driver12,13. This device is similar to the infinite horizon impactors, as it uses short-distance compressions to cause spinal cord injuries. However, it has various limitations in that initial determination of the zero point will cause errors due to the presence of the cerebrospinal fluid6,14. In summary, there are many instruments that can be used to develop spinal cord injury contusion animal models, but they all have some limitations that lead to insufficient accuracy and reproducibility of animal models. Therefore, in order to more accurately, conveniently and reproducibly create mouse contusion models of spinal cord injury, an automated and intelligent spinal cord injury impactor is needed.
We present a novel spinal cord injury impactor, Guangzhou Jinan University smart spinal cord injury system (G smart SCI system; Figure 1), for producing spinal cord injury contusion models. The device uses a laser rangefinder as a positioning device, combined with an automated mobile platform to automate strikes according to set strike parameters, including strike speed, strike depth and dwell time. Automated operation reduces human factors and improves the accuracy as well as reproducibility of animal models.

Autore in primo piano: Approfondimento sulle innovazioni nella ricerca sulle lesioni del midollo spinale

Impattatore automatizzato per il modello di lesione del midollo spinale contusivo nei topi

My research scope includes the pathogenesis and the treatment methods of spinal cord injury. Our recent research has found that various biomaterials can promote the repair of spinal cord injury in mice through antioxidant stress. The development of biomaterial sensors, technologies, and the gene modification technology, as well as the optimization of spinal cord injury models are advancing our research field.Due to compress and incompletely understood mechanism of spinal cord injury, it is currently difficult to cure spinal cord injury using a single intervention. In the future, multiple intervention methods may be needed for research. We found that mental immediate compress can participate in the treatment and the repair of spinal cord injury in animals through antioxidant stress.

Valutazione della contusione della lesione nei topi per l'analisi della lesione spinale

Per iniziare, calcola i punteggi della Basso Mouse Scale per i topi a partire dal primo giorno postoperatorio. Il giorno 30 dopo l'intervento chirurgico, eseguire i test comportamentali tra cui i test della passerella, del fallo del piede e del rotarod. Per il test della passerella, registra il topo che cammina per una distanza di 45 centimetri con una durata massima della corsa di otto secondi.Per eseguire il test footfault, registrare il mouse che cammina per 60 passi. Per il test del rotarod, notare il tempo impiegato dal mouse per cadere dal rotarod che gira a una velocità di 20 giri al minuto. Il 31° giorno dopo l'operazione, rimuovere con cautela il midollo spinale del topo sottoposto a eutanasia.Tagliare il cordone asportato cinque millimetri sopra e sotto il sito della lesione per preparare l'inclusione della paraffina. Preparare cinque sezioni micrometriche di paraffina dal centro della lesione del midollo spinale inflitta con un microtomo ed eseguire la colorazione con ematossilina ed eosina. Condurre analisi statistiche utilizzando software commerciali.Dopo un mese, i topi nel gruppo di 0,5 millimetri hanno mostrato da quattro a sei punteggi postoperatori e si sono ripresi in modo simile al gruppo fittizio. I topi nei gruppi di 0,8 millimetri e 1,1 millimetri hanno avuto uno o due punteggi postoperatori. Il gruppo da 0,8 millimetri ha recuperato da quattro a sei punti dopo un mese, mentre il gruppo da 1,1 millimetri si è ripreso a malapena.Nel test del fallo del piede, non sono state osservate differenze significative nel difetto del piede degli arti posteriori tra il gruppo di 0,5 millimetri e il gruppo fittizio. I topi nel gruppo di 1,1 millimetri avevano il 100% di footfault. I gruppi da 0,8 millimetri e 1,1 millimetri hanno mostrato risultati significativamente diversi nel test del rotarod.Tuttavia, i gruppi fittizi e 0,5 millimetri erano simili. Tutti i gruppi hanno risposto in modi significativamente diversi al test della passerella. La resezione spinale ha dimostrato vari gradi di danno nelle immagini del midollo spinale e nelle sezioni colorate con ematossilina ed eosina.

Research

JoVE Journal

Neuroscience

Evaluation of Injury Contusion in Mice For Spinal Injury Analysis

Automated Impactor for Contusive Spinal Cord Injury Model in Mice

Spinal cord injury (SCI) due to traumatic injuries such as car accidents and falls is associated with permanent spinal cord dysfunction. Creation of ...

Ricerca

Neuroscienze

Mice T10 Spinal Laminectomy and Contusion with the G Smart SCI System For Spinal Injury Analysis

Laminectomia spinale T10 e contusione di topi con il sistema G Smart SCI per l'analisi delle lesioni spinali