evaluation of injury contusion in mice for spinal injury analysis

En kontusionsenhed til rygmarvsskade til nøjagtige musemodeller

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.

Forfatter Spotlight: Indsigt i innovationer inden for rygmarvsskadeforskning

Automatiseret slaglegeme til kontusiv rygmarvsskademodel hos mus

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.

Evaluering af skadekontusion hos mus til spinalskadeanalyse

Til at begynde med skal du beregne Basso Mouse Scale-scorerne for mus startende fra den første postoperative dag. På dag 30 efter operationen skal du udføre adfærdstestene, herunder catwalk, fodfejl og rotarodtest. Til catwalk-testen skal du registrere musen, der går en afstand på 45 centimeter med en maksimal løbevarighed på otte sekunder.For at udføre fodfejltesten skal du registrere musen, der går 60 trin. For rotarod-testen skal du notere den tid, det tager for musen at falde af rotarodspinding med en hastighed på 20 omdrejninger pr. Minut. På den 31. dag efter operationen skal du forsigtigt fjerne rygmarven på den aflivede mus.Skær den udskårne ledning fem millimeter over og under skadestedet for at forberede paraffinindlejring. Forbered fem mikrometer paraffinsektioner fra midten af den påførte rygmarvsskade med et mikrotom, og udfør hæmatoxylin og eosinfarvning. Udfør statistisk analyse ved hjælp af kommerciel software.Efter en måned viste mus i 0,5 millimeter-gruppen fire til seks postoperative scoringer og kom sig på samme måde som sham-gruppen. Mus i 0,8 millimeter og 1,1 millimeter grupperne havde en til to postoperative scorer. 0,8 millimeter-gruppen kom sig til fire til seks scoringer efter en måned, mens 1,1 millimeter-gruppen næppe kom sig.I fodfejltesten blev der ikke observeret signifikante forskelle i fodfejl i bagbenene mellem 0,5 millimeter-gruppen og skingruppen. Musene i 1,1 millimeter-gruppen havde 100% fodfejl. 0,8 millimeter og 1,1 millimeter grupperne viste signifikant forskellige resultater i rotarod-testen.Imidlertid var skam- og 0, 5 millimeter-grupperne ens. Alle grupper reagerede på signifikant forskellige måder i catwalk-testen. Spinal resektion viste varierende grader af skade i rygmarvsbillederne såvel som i hæmatoxylin og eosin farvede sektioner.

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 ...

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

Mus T10 spinal laminektomi og kontusion med G Smart SCI System til spinal skadeanalyse