Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, 60612, USA.
Synapse. 2013 Jul;67(7):427-53. doi: 10.1002/syn.21645. Epub 2013 Mar 19.
Spinal cord injuries usually produce loss or impairment of sensory, motor and reflex function below the level of damage. In the absence of functional regeneration or manipulations that promote regeneration, spontaneous improvements in motor functions occur due to the activation of multiple compensatory mechanisms in animals and humans following the partial spinal cord injury. Many studies were performed on quantitative evaluation of locomotor recovery after induced spinal cord injury in animals using behavioral tests and scoring techniques. Although few studies on rodents have led to clinical trials, it would appear imperative to use nonhuman primates such as macaque monkeys in order to relate the research outcomes to recovery of functions in humans. In this review, we will discuss some of our research evidences concerning the degree of spontaneous recovery in bipedal locomotor functions of bonnet monkeys that underwent spinal cord hemisection/contusion lesions. To our knowledge, this is the first report to discuss on the extent of spontaneous recovery in bipedal locomotion of macaque monkeys through the application of footprint analyzing technique. In addition, the results obtained were compared with the published data on recovery of quadrupedal locomotion of spinally injured rodents. We propose that the mechanisms underlying spontaneous recovery of functions in spinal cord lesioned monkeys may be correlated to the mature function of spinal pattern generator for locomotion under the impact of residual descending and afferent connections. Moreover, based on analysis of motor functions observed in locomotion in these subjected monkeys, we understand that spinal automatism and development of responses by afferent stimuli from outside the cord could possibly contribute to recovery of paralyzed hindlimbs. This report also emphasizes the functional contribution of progressive strengthening of undamaged nerve fibers through a collateral sprouts/synaptic plasticity formed in partially lesioned cord of monkeys.
脊髓损伤通常会导致损伤以下水平的感觉、运动和反射功能丧失或受损。在缺乏功能再生或促进再生的操作的情况下，动物和人类在部分脊髓损伤后，由于多个补偿机制的激活，运动功能会自发改善。许多研究使用行为测试和评分技术对动物诱导性脊髓损伤后的运动功能恢复进行了定量评估。尽管少数啮齿动物研究已进入临床试验阶段，但似乎必须使用非人灵长类动物（如猕猴），以便将研究结果与人类功能恢复相关联。在这篇综述中，我们将讨论一些关于我们的研究证据，涉及接受脊髓半横断/挫伤病变的绢毛猴双足运动功能的自发恢复程度。据我们所知，这是第一篇应用足迹分析技术讨论猕猴双足运动自发恢复程度的报告。此外，我们还将获得的结果与已发表的关于脊髓损伤啮齿动物四肢运动恢复的数据进行了比较。我们提出，脊髓损伤猴子功能自发恢复的机制可能与残留下行和传入连接影响下脊髓运动模式发生器的成熟功能有关。此外，基于对这些受试猴子运动中观察到的运动功能的分析，我们了解到脊髓自动性和来自脊髓外的传入刺激产生的反应的发展可能有助于瘫痪后肢的恢复。本报告还强调了通过在猴子部分损伤的脊髓中形成侧支芽/突触可塑性，对未受损神经纤维进行渐进强化的功能贡献。
