Tennant Kelly A, Kerr Abigail L, Adkins DeAnna L, Donlan Nicole, Thomas Nagheme, Kleim Jeffrey A, Jones Theresa A
University of Texas at Austin, Austin, TX, USA University of Victoria, Victoria, British Columbia, Canada
Illinois Wesleyan University, Bloomington, IL, USA.
Neurorehabil Neural Repair. 2015 Feb;29(2):193-202. doi: 10.1177/1545968314541329. Epub 2014 Jul 8.
The incidence of stroke in adulthood increases with advancing age, but there is little understanding of how poststroke treatment should be tailored by age.
The goal of this study was to determine if age and task specificity of rehabilitative training affect behavioral improvement and motor cortical organization after stroke.
Young and aged mice were trained to proficiency on the Pasta Matrix Reaching Task prior to lesion induction in primary motor cortex with endothelin-1. After a short recovery period, mice received 9 weeks of rehabilitative training on either the previously learned task (Pasta Matrix Reaching), a different reaching task (Tray Reaching), or no training. To determine the extent of relearning, mice were tested once weekly on the Pasta Matrix Reaching Task. Mice then underwent intracortical microstimulation mapping to resolve the remaining forelimb movement representations in perilesion motor cortex.
Although aged mice had significantly larger lesions compared with young mice, Pasta Matrix Reaching served as effective rehabilitative training for both age-groups. Young animals also showed improvement after Tray Reaching. Behavioral improvement in young mice was associated with an expansion of the rostral forelimb area ("premotor" cortex), but we failed to see reorganization in the aged brain, despite similar behavioral improvements.
Our results indicate that reorganization of motor cortex may be limited by either aging or greater tissue damage, but the capacity to improve motor function via task-specific rehabilitative training continues to be well maintained in aged animals.
成年期中风的发病率随年龄增长而增加，但对于如何根据年龄调整中风后的治疗方案却知之甚少。
本研究的目的是确定康复训练的年龄和任务特异性是否会影响中风后的行为改善和运动皮层组织。
在通过内皮素-1诱导初级运动皮层损伤之前，对年轻和老年小鼠进行训练，使其熟练掌握意大利面矩阵抓取任务。经过短暂的恢复期后，小鼠接受为期9周的康复训练，训练内容为之前学过的任务（意大利面矩阵抓取）、另一种抓取任务（托盘抓取）或不进行训练。为了确定重新学习的程度，每周对小鼠进行一次意大利面矩阵抓取任务测试。然后，对小鼠进行皮层内微刺激映射，以解析损伤周围运动皮层中剩余的前肢运动表征。
尽管老年小鼠的损伤明显大于年轻小鼠，但意大利面矩阵抓取对两个年龄组都是有效的康复训练。年轻动物在托盘抓取训练后也表现出改善。年轻小鼠的行为改善与喙侧前肢区域（“运动前”皮层）的扩大有关，但尽管行为改善相似，我们在老年大脑中未观察到重组。
我们的结果表明，运动皮层的重组可能受到衰老或更大组织损伤的限制，但通过特定任务的康复训练改善运动功能的能力在老年动物中仍能得到很好的维持。
