脊髓背根神经节切除模型——周围神经趋化性再生定量研究模型的建立

Establishment of Dorsal Reot Ganglion Resection Model for Quantifative Evalution of Selctive Regeneration of Peripheral Nerve

为了建立脊髓背根神经节(dorsal root ganglion,DRG)切除模型,选择性地使感觉神经纤维溃变而保持运动神经纤维的正常功能,从而为周围神经趋化性再生的定量评价提供有效的研究方法。将雄性SD大鼠20只,随机分为两组,每组10只动物。大体解剖组:解剖大鼠坐骨神经的神经根组成及DRG的位置。DRG切除组:切除支配大鼠坐骨神经的每个神经根的DRG。观察大鼠DRG切除后步态变化及足部溃疡情况。切除后3周,取双侧坐骨神经、胫神经、腓神经及腓肠神经行髓鞘染色,观察各神经中感觉神经纤维溃变情况;行美兰复红染色,计算机图像分析,运动神经纤维计数。发现大鼠坐骨神经由L4、L5、L6神经干组成,DRG位于腹、背侧根汇合处近心端1mm处。DRG切除术后,大鼠步态失去协调性,但展趾宽度无明显改变。DRG切除后3周,髓鞘染色显示腓肠神经中有髓神经纤维髓鞘完全溃变,坐骨神经、胫神经、腓神经中部分有髓神经纤维发生溃变。美兰复红染色、计算机图像分析计数显示坐骨神经及三个主要分支内,有髓运动神经纤维分别占其总数的58.4%、54.6%、45.4%、0。说明DRG切除模型,可以有效区分感觉和运动神经纤维,能够较好地定量评价周围神经趋化性再生的效果。通过比较不同桥接材料和不同修复方法的错接率,从而定量评价各修复材料和方法的趋化性再生效果。

To establish dorsal root ganglion（DRG） resection model, in which the sensory nerve fibers were selectively degenerated while the motor nerve fibers remained intact and unaffected and to provide a effective method for quantitative evaluation of selective regeneration of peripheral nerve, 20 SD rats were randomly divided into 2 groups, with 10 rats in each group. In the gross anatomy group, the rat sciatic nerve was dissected to identify the nerve roots and to localize the DRG. In the DRG resection group, all DRGs of left sciatic nerve were removed. Histology staining was to observe the degeneration of sensory nerve fibers. Compute image analysis was to measure the number of motor nerve fiber. Rat sciatic nerve was at the conjunction of ventral and dorsal nerve roots, composed of L4, L5 and L6 nerve roots. The DRG was situated 1 mm near the proximal nerve part. After the DRGs were resected 3 weeks, the myelinated nerve fibers in the sural nerve were completely degenerated showing by the fast -blue staining. The myelinated motor nerve fibers accounts for 58.4%, 54.6%, 45.4% and 0 in sciatic nerve , tibial nerve, peroneal nerve and sural nerve respectively showing by compute image analysis. The DRG resection model can effectively distinguish the sensory and motor nerve fibers and can be used for quantitative evaluation of selective regeneration of peripheral nerve. Effectiveness of selective nerve regeneration in different grafting materials and repair methods can be evaluated quantitatively by comparison of its regeneration misdirection rate.