Prosser-Loose Erin J, Hassan Atiq, Mitchell Gordon S, Muir Gillian D
1 Biomedical Sciences, WCVM, University of Saskatchewan , Saskatoon, Saskatchewan, Canada .
2 Comparative Biosciences, University of Wisconsin-Madison , Madison, Wisconsin.
J Neurotrauma. 2015 Sep 15;32(18):1403-12. doi: 10.1089/neu.2014.3789. Epub 2015 May 7.
The reduction of motor, sensory and autonomic function below the level of an incomplete spinal cord injury (SCI) has devastating consequences. One approach to restore function is to induce neural plasticity as a means of augmenting spontaneous functional recovery. Acute intermittent hypoxia (AIH-brief exposures to reduced O2 levels alternating with normal O2 levels) elicits plasticity in respiratory and nonrespiratory somatic spinal systems, including improvements in ladder walking performance in rats with incomplete SCI. Here, we determined whether delayed treatment with AIH, with or without concomitant motor training, could improve motor recovery in a rat model of incomplete cervical SCI. In a randomized, blinded, sham-controlled study, rats were exposed to AIH for 7 days beginning at 4 weeks post-SCI, after much spontaneous recovery on a horizontal ladder-crossing task had already occurred. For up to 2 months post-treatment, AIH-treated rats made fewer footslips on the ladder task compared with sham-treated rats. Importantly, concomitant ladder-specific motor training was needed to elicit AIH-induced improvements, such that AIH-treated SCI rats receiving no motor training or nontask-specific treadmill training during the treatment week did not show improvements over sham-treated rats with SCI. AIH treatment combined with task-specific training did not improve recovery on two different reach-to-grasp tasks, however, nor on tasks involving unskilled forepaw use. In brief, our results indicate that task-specific training is needed for AIH to improve ladder performance in a rat model of incomplete cervical SCI.
不完全性脊髓损伤（SCI）平面以下运动、感觉和自主神经功能的减退会产生毁灭性后果。一种恢复功能的方法是诱导神经可塑性，以此增强自发的功能恢复。急性间歇性低氧（AIH——短暂暴露于低氧水平并与正常氧水平交替）可引发呼吸和非呼吸性躯体脊髓系统的可塑性，包括改善不完全性SCI大鼠的阶梯行走表现。在此，我们确定延迟给予AIH治疗（无论是否伴有运动训练）是否能改善不完全性颈髓SCI大鼠模型的运动恢复。在一项随机、盲法、假手术对照研究中，大鼠在SCI后4周开始接受7天的AIH暴露，此时它们在水平阶梯跨越任务上已经有了大量自发恢复。在治疗后的长达2个月时间里，与假手术组大鼠相比，接受AIH治疗的大鼠在阶梯任务中出现的失足次数更少。重要的是，需要同时进行特定于阶梯任务的运动训练才能引发AIH诱导的改善，因此在治疗周期间未接受运动训练或非任务特定跑步机训练的接受AIH治疗的SCI大鼠并未比接受假手术的SCI大鼠表现出更好的恢复。然而，AIH治疗与特定任务训练相结合在两项不同的抓握任务以及涉及非熟练前爪使用的任务中并未改善恢复情况。简而言之，我们的结果表明，在不完全性颈髓SCI大鼠模型中，AIH要改善阶梯表现需要特定任务训练。
