Engesser-Cesar Christie, Ichiyama Ronaldo M, Nefas Amber L, Hill Mary Ann, Edgerton V Reggie, Cotman Carl W, Anderson Aileen J
Institute for Brain Aging and Dementia, University of California, Irvine, USA.
Eur J Neurosci. 2007 Apr;25(7):1931-9. doi: 10.1111/j.1460-9568.2007.05469.x.
Exercise, through manual step training, robotic step training or voluntary wheel running, is emerging as a promising therapy after spinal cord injury (SCI). Animal models provide a tool to investigate the mechanisms by which physical activity influences recovery from SCI. In the present study, we extend previous experiments showing improved recovery after SCI with both pre- and post-injury running in a flat-surface running wheel and investigate mechanisms of recovery. We tested a clinically relevant model using post-injury wheel running, in which we provided mice with access to wheels either 3 days or 7 days/week. Open field behavior, observed for 15 weeks following moderate T9 contusion injury, showed a significant linear increase in locomotor improvements across groups, sedentary, 3-day runners and 7-day runners. Kinematic analysis of treadmill walking revealed that both wheel-running groups, 3 and 7 days/week, improved stepping ability compared with sedentary controls. Stereological quantification of neuron number in the injured segment of the spinal cord revealed no differences between the groups. However, stereological quantification of serotonin immunostaining using isotropic virtual planes showed increases in serotonin fiber length caudal to the lesion in the running groups. These observations suggest that improvement in function may be related to changes in serotonin fibers immediately caudal to the injury epicenter.
通过手动阶梯训练、机器人阶梯训练或自主轮转跑步进行的运动，正逐渐成为脊髓损伤（SCI）后一种有前景的治疗方法。动物模型为研究身体活动影响SCI恢复的机制提供了一种工具。在本研究中，我们扩展了先前的实验，这些实验表明在平面转轮中进行损伤前和损伤后的跑步均能改善SCI后的恢复情况，并研究了恢复机制。我们使用损伤后轮转跑步测试了一种临床相关模型，在该模型中，我们为小鼠提供每周3天或7天使用转轮的机会。在中度T9挫伤损伤后观察15周的旷场行为显示，与久坐组、3天跑步组和7天跑步组相比，各运动组的运动能力改善呈显著线性增加。跑步机行走的运动学分析表明，每周3天和7天的转轮跑步组与久坐对照组相比，步幅能力均有所提高。脊髓损伤节段神经元数量的体视学定量分析显示，各组之间无差异。然而，使用各向同性虚拟平面进行的血清素免疫染色体视学定量分析显示，跑步组损伤部位尾侧的血清素纤维长度增加。这些观察结果表明，功能的改善可能与损伤震中尾侧紧邻部位血清素纤维的变化有关。
