Vagus nerve stimulation intensity influences motor cortex plasticity
Vagus nerve stimulation intensity influences motor cortex plasticity
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DOI：
10.1016/j.brs.2018.10.017
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发表时间：
2019-03-01
影响因子：
7.7
通讯作者：
Hays, Seth A.
中科院分区：
文献类型：
--
作者：
Morrison, Robert A.;Hulsey, Daniel R.;Hays, Seth A.
背景：迷走神经刺激(VNS)配合前肢运动训练可促进运动皮质运动表征的重组。以前的研究表明，VNS强度与大脑其他区域的可塑性之间存在倒U型关系，即中等强度的VNS比低强度或高强度的VNS产生更大的皮质可塑性。然而，VNS强度与运动皮质可塑性之间的关系尚不清楚。目的：在本研究中，我们试图验证VNS强度与大鼠运动皮质可塑性程度呈倒U形关系的假设。方法：训练大鼠进行强调使用前肢近端肌肉系统的杠杆按压任务。一旦熟练，大鼠再接受5天的行为训练，其中低强度VNS(0.4 mA)、中等强度VNS(0.8 mA)、高强度VNS(1.6 mA)或假刺激配合前肢运动。行为训练结束后24 h，用皮层内微刺激(ICMS)记录运动皮质的运动表征。结果：0.8 mA的迷走神经刺激使运动皮质近侧前肢的运动表征显著增加。结论：0.8 mA中等强度的VNS对运动皮质的可塑性增强效果最好，而0.4 mA和1.6 mA的低强度VNS不能增强运动皮质的可塑性。运动皮质的可塑性表现为VNS强度的倒U形功能，类似于以前在听觉皮质的发现。(C)2018 Elsevier Inc.保留所有权利。
Background: Vagus nerve stimulation (VNS) paired with forelimb motor training enhances reorganization of movement representations in the motor cortex. Previous studies have shown an inverted-U relationship between VNS intensity and plasticity in other brain areas, such that moderate intensity VNS yields greater cortical plasticity than low or high intensity VNS. However, the relationship between VNS intensity and plasticity in the motor cortex is unknown.Objective: In this study we sought to test the hypothesis that VNS intensity exhibits an inverted-U relationship with the degree of motor cortex plasticity in rats.Methods: Rats were taught to perform a lever pressing task emphasizing use of the proximal forelimb musculature. Once proficient, rats underwent five additional days of behavioral training in which low intensity VNS (0.4 mA), moderate intensity VNS (0.8 mA), high intensity VNS (1.6 mA), or sham stimulation was paired with forelimb movement. 24 h after the completion of behavioral training, intracortical microstimulation (ICMS) was used to document movement representations in the motor cortex.Results: VNS delivered at 0.8 mA caused a significant increase in motor cortex proximal forelimb representation compared to training alone. VNS delivered at 0.4 mA and 1.6 mA failed to cause a significant expansion of proximal forelimb representation.Conclusion: Moderate intensity 0.8 mA VNS optimally enhances motor cortex plasticity while low intensity 0.4 mA and high intensity 1.6 mA VNS fail to enhance plasticity. Plasticity in the motor cortex exhibits an inverted-U function of VNS intensity similar to previous findings in auditory cortex. (C) 2018 Elsevier Inc. All rights reserved.