Cherry-Allen Kendra M, Gidday Jeff M, Lee Jin-Moo, Hershey Tamara, Lang Catherine E
Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri;
Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri; Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri; Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri;
J Neurophysiol. 2015 Jun 1;113(10):3708-19. doi: 10.1152/jn.01028.2014. Epub 2015 Apr 1.
Brief bouts of sublethal ischemia have been shown to protect exposed tissue (ischemic conditioning) and tissues at remote sites (remote ischemic conditioning) against subsequent ischemic challenges. Given that the mechanisms of this protective phenomenon are multifactorial and epigenetic, we postulated that remote limb ischemic conditioning (RLIC) might enhance mechanisms responsible for neural plasticity, and thereby facilitate learning. Specifically, we hypothesized that conditioning of the nervous system with RLIC, achieved through brief repetitive limb ischemia prior to training, would facilitate the neurophysiological processes of learning, thus making training more effective and more long-lasting. Eighteen healthy adults participated in this study; nine were randomly allocated to RLIC and nine to sham conditioning. All subjects underwent seven consecutive weekday sessions and 2-wk and 4-wk follow-up sessions. We found that RLIC resulted in significantly greater motor learning and longer retention of motor performance gains in healthy adults. Changes in motor performance do not appear to be due to a generalized increase in muscle activation or muscle strength and were not associated with changes in serum brain-derived neurotrophic factor (BDNF) concentration. Of note, RLIC did not enhance cognitive learning on a hippocampus-dependent task. While future research is needed to establish optimal conditioning and training parameters, this inexpensive, clinically feasible paradigm might ultimately be implemented to enhance motor learning in individuals undergoing neuromuscular rehabilitation for brain injury and other pathological conditions.
短暂的亚致死性缺血发作已被证明可保护暴露组织（缺血预处理）和远处组织（远程缺血预处理）免受后续缺血挑战。鉴于这种保护现象的机制是多因素且涉及表观遗传学的，我们推测远程肢体缺血预处理（RLIC）可能增强负责神经可塑性的机制，从而促进学习。具体而言，我们假设通过训练前短暂重复的肢体缺血实现的RLIC对神经系统的预处理将促进学习的神经生理过程，从而使训练更有效且更持久。18名健康成年人参与了这项研究；9人被随机分配到RLIC组，9人被分配到假预处理组。所有受试者连续五个工作日接受训练，并在2周和4周时进行随访。我们发现，RLIC在健康成年人中导致显著更好的运动学习和更长时间地保持运动表现提升。运动表现的变化似乎不是由于肌肉激活或肌肉力量的普遍增加，并且与血清脑源性神经营养因子（BDNF）浓度的变化无关。值得注意的是，RLIC并未增强在依赖海马体的任务上的认知学习。虽然需要未来的研究来确定最佳的预处理和训练参数，但这种廉价、临床上可行的模式最终可能会被用于增强因脑损伤和其他病理状况而接受神经肌肉康复的个体的运动学习。
