臂丛根性伤后运动神经元的存活及再生路径研究

Survival and Pathway of Regenerative Motoneurons after Brachial Plexus Root Injury

目的观察臂丛神经不同损伤后脊髓前角运动神经元的存活及再生轴突的路径选择,探讨其与运动功能恢复的关系。方法选用48只健康成年雄性SD大鼠,随机分为挫伤组、切断组、撕脱组和对照组。术后2个月进行Grooming实验。处死前3d肌皮神经肌支或皮支注射荧光金逆行追踪标记,处死后取脊髓C5-8节段标本,计数再生脊髓运动神经元数;中性红复染计数存活神经元数。结果各组存活神经元数撕脱组(881±76)<切断组(1005±89)<挫伤组(1126±25)<对照组(1900±39);各组皮支均标记到10～20个神经元,而肌支标记到大量的神经元。Grooming实验,挫伤组(3.42级)明显好于撕脱组(1.75级)及切断组(1.75级)。结论臂丛神经根性损伤后脊髓前角运动神经元的再生路径为肌支路径,不同损伤后存活的神经元数不同,功能恢复的程度也不同。

Objective To observe the survival and pathway of regenerative axons of spinal motoneurons following root injury of brachial plexus（BPI）and to investigate the correlation between the pathway of regenerative axons and the recovery of motor function.Methods48 adult male SD rats were randomly divided into four groups：crush group,cut group,avulsion group and the control group.2 months later,the functional recovery was evaluated with Grooming test.Fluorogold labeled regenerative motoneurons retrogradely when injected into the motor or sensory branch of musculocutaneous nerve.3 d later,the C5-8 spinal cord were harvested and the regenerative motoneurons were counted.The survival neurons were counted with neutral red staining.ResultsThe number of survival neurons in the cut group（1005±89）were more than that of the avulsion group（881±76）,but less than the crush group（1126±25）.The control group was the most（1900±39）.The regenerative motoneurons reinnervated motor branch were much more than that of the sensory branch in all groups.For the Grooming test,the grade in the crush group（3.42）was much higher than that of the avulsion（1.75）and cut（1.75）group.ConclusionRegenerative axons of spinal motoneurons reinnervate the motor branch after BPI.The number of survival neurons is different after different injuries,which associated with the motor functional recovery.