Houle John D, Amin Arthi, Cote Marie-Pascale, Lemay Michel, Miller Kassi, Sandrow Harra, Santi Lauren, Shumsky Jed, Tom Veronica
Department of Neurobiology and Anatomy, Drexel University College of Medicine, USA.
J Vis Exp. 2009 Nov 20(33):1324. doi: 10.3791/1324.
Traumatic injury to the spinal cord (SCI) causes death of neurons, disruption of motor and sensory nerve fiber (axon) pathways and disruption of communication with the brain. One of the goals of our research is to promote axon regeneration to restore connectivity across the lesion site. To accomplish this we developed a peripheral nerve (PN) grafting technique where segments of sciatic nerve are either placed directly between the damaged ends of the spinal cord or are used to form a bridge across the lesion. There are several advantages to this approach compared to transplantation of other neural tissues; regenerating axons can be directed towards a specific target area, the number and source of regenerating axons is easily determined by tracing techniques, the graft can be used for electrophysiological experiments to measure functional recovery associated with axons in the graft, and it is possible to use an autologous nerve to reduce the possibility of graft rejection. In our lab we have performed both autologous (donor and recipient are the same animal) and heterologous (donor and recipient are different animals) grafts with comparable results. This approach has been used successfully in both acute and chronic injury situations. Regenerated axons that reach the distal end of the PN graft often fail to extend back into the spinal cord, so we use microinjections of chondroitinase to degrade inhibitory molecules associated with the scar tissue surrounding the area of SCI. At the same time we have found that providing exogenous growth and trophic molecules encourages longer distance axonal regrowth into the spinal cord. Several months after transplantation we perform a variety of anatomical, behavioral and electrophysiological tests to evaluate the recovery of function in our spinal cord injured animals. This experimental approach has been used successfully in several spinal cord injury models, at different levels of injury and in different species (mouse, rat and cat). Importantly, the peripheral nerve grafting approach is effective in promoting regeneration by acute and chronically injured neurons.
脊髓创伤性损伤（SCI）会导致神经元死亡、运动和感觉神经纤维（轴突）通路中断以及与大脑的通讯中断。我们研究的目标之一是促进轴突再生，以恢复损伤部位的连接。为实现这一目标，我们开发了一种周围神经（PN）移植技术，即将坐骨神经段直接置于脊髓受损端之间，或用于在损伤部位搭建桥梁。与其他神经组织移植相比，这种方法有几个优点；再生轴突可被引导至特定目标区域，通过追踪技术可轻松确定再生轴突的数量和来源，该移植物可用于电生理实验，以测量与移植物中轴突相关的功能恢复情况，并且可以使用自体神经来降低移植物排斥的可能性。在我们实验室，我们进行了自体（供体和受体为同一只动物）和异体（供体和受体为不同动物）移植，结果相当。这种方法已在急性和慢性损伤情况下成功应用。到达PN移植物远端的再生轴突往往无法延伸回脊髓，因此我们使用软骨素酶显微注射来降解与SCI区域周围瘢痕组织相关的抑制分子。同时，我们发现提供外源性生长和营养分子可促进轴突向脊髓内更长距离的生长。移植数月后，我们进行各种解剖学、行为学和电生理测试，以评估脊髓损伤动物的功能恢复情况。这种实验方法已在几种脊髓损伤模型中成功应用，损伤程度不同，物种也不同（小鼠、大鼠和猫）。重要的是，周围神经移植方法在促进急性和慢性损伤神经元的再生方面是有效的。
