evaluation of injury contusion in mice for spinal injury analysis

正確なマウスモデルのための脊髄損傷挫傷装置

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.

著者スポットライト:脊髄損傷研究におけるイノベーションへの洞察

マウスの挫傷性脊髄損傷モデルのための自動インパクター

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.

脊髄損傷解析のためのマウスの損傷挫傷の評価

まず、術後最初の日から始まるマウスのバッソマウススケールスコアを計算します。手術後30日目に、キャットウォーク、フットフォルト、ロータロッドテストなどの行動テストを実施します。キャットウォークテストでは、マウスが45センチメートルの距離を歩いたとき、最大走行時間を8秒で記録します。フットフォールトテストを実行するには、マウスの歩行を60歩記録します。ロータロッドテストでは、毎分20回転の速度で回転するロータロッドからマウスが落ちるのにかかる時間に注意してください。術後31日目に、安楽死させたマウスの脊髄を慎重に取り除きます。切除したコードを損傷部位の上下5ミリメートルで切断し、パラフィン包埋の準備をします。負った脊髄損傷の中心から5マイクロメートルのパラフィン切片をミクロトームで作製し、ヘマトキシリンとエオシンの染色を行います。市販のソフトウェアを使用して統計分析を行います。1カ月後、0.5ミリメートル群のマウスは術後スコアが4〜6点を示し、偽群と同様に回復した。0.8ミリメートル群と1.1ミリメートル群のマウスは、術後スコアが1〜2でした。0.8ミリ群は1カ月後に4〜6点に回復したが、1.1ミリ群はほとんど回復しなかった。足障害試験では、0.5mm群と偽群で後肢足の有意差は認められなかった。1.1ミリ群のマウスは100%の足障害を持っていた。0.8ミリメートル群と1.1ミリメートル群では、ロータロッド試験で有意に異なる結果を示しました。しかし、偽グループと0.5ミリメートルグループは類似していました。キャットウォークテストでは、すべてのグループの反応が大きく異なっていました。脊椎切除術では、脊髄画像、ならびにヘマトキシリンおよびエオシン染色切片にさまざまな程度の損傷が認められた。

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 ...

神経科学

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

脊椎損傷分析のためのG Smart SCIシステムによるマウスT10脊椎椎弓切除術および挫傷