You Si-Wei, Chen Bing-Yao, Liu Hui-Ling, Lang Bing, Xia Jie-Lai, Jiao Xi-Ying, Ju Gong
Institute of Neurosciences, The Fourth Military Medical University, Xi'an, 710032, China.
Restor Neurol Neurosci. 2003;21(1-2):39-45.
A major issue in analysis of experimental results after spinal cord injury is spontaneous functional recovery induced by remaining nerve fibers. The authors investigated the relationship between the degree of locomotor recovery and the percentage and location of the fibers that spared spinal cord transection.
The spinal cords of 12 adult rats were transected at T9 with a razor blade, which often resulted in sparing of nerve fibers in the ventral spinal cord. The incompletely-transected animals were used to study the degree of spontaneous recovery of hindlimb locomotion, evaluated with the BBB rating scale, in correlation to the extent and location of the remaining fibers.
Incomplete transection was found in the ventral spinal cord in 42% of the animals. The degree of locomotor recovery was highly correlated with the percentage of the remaining fibers in the ventral and ventrolateral funiculi. In one of the rats, 4.82% of remaining fibers in unilateral ventrolateral funiculus were able to sustain a certain recovery of locomotion.
Less than 5% of remaining ventrolateral white matter is sufficient for an unequivocal motor recovery after incomplete spinal cord injury. Therefore, for studies with spinal cord transection, the completeness of sectioning should be carefully checked before any conclusion can be reached. The fact that the degree of locomotor recovery is correlated with the percentage of remaining fibers in the ventrolateral spinal cord, exclusive of most of the descending motor tracts, may imply an essential role of propriospinal connections in the initiation of spontaneous locomotor recovery.
脊髓损伤后实验结果分析中的一个主要问题是由残留神经纤维诱导的自发功能恢复。作者研究了运动恢复程度与脊髓横断后残留纤维的百分比及位置之间的关系。
用剃须刀片在12只成年大鼠的T9水平横断脊髓，这常常导致脊髓腹侧神经纤维的保留。将不完全横断的动物用于研究后肢运动的自发恢复程度，采用BBB评分量表进行评估，并与残留纤维的范围和位置相关联。
42%的动物脊髓腹侧存在不完全横断。运动恢复程度与腹侧和腹外侧索中残留纤维的百分比高度相关。在其中一只大鼠中，单侧腹外侧索中4.82%的残留纤维能够维持一定程度的运动恢复。
脊髓不完全损伤后，残留腹外侧白质少于5%足以实现明确的运动恢复。因此，对于脊髓横断的研究，在得出任何结论之前都应仔细检查横断的完整性。运动恢复程度与腹外侧脊髓中残留纤维的百分比相关，而不包括大多数下行运动束，这一事实可能意味着脊髓 propriospinal 连接在自发运动恢复起始中起着重要作用。
