Differential modulation of motor cortex excitability in BDNF Met allele carriers following experimentally induced and use-dependent plasticity
Differential modulation of motor cortex excitability in BDNF Met allele carriers following experimentally induced and use-dependent plasticity
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DOI：
10.1111/j.1460-9568.2012.08177.x
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发表时间：
2012-09-01
影响因子：
3.4
通讯作者：
Semmler, John G.
中科院分区：
文献类型：
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作者：
Cirillo, John;Hughes, James;Semmler, John G.
本研究的目的是调查具有脑源性神经营养因子 (BDNF) 基因三种变体之一的健康年轻受试者在实验诱导和依赖于使用的可塑性干预措施后如何调节运动皮层兴奋性。从 12 Val/Val、10 Val/Met 和 7 Met/Met 基因型（年龄 1839 岁）的右侧第一背侧骨间 (FDI) 肌肉获得肌电图记录。左半球经颅磁刺激用于评估 FDI 运动诱发电位 (MEP) 的变化，在三种独立的干预措施后，包括配对联想刺激、简单的弹道任务和使用食指的复杂视觉运动跟踪任务。 Val/Val 受试者在所有干预后 FDI MEP 均增加（= 25%，P < 0.01），而 Met 等位基因携带者仅在简单运动任务后表现出 MEP 增加（= 26%，P < 0.01）。与简单运动任务相比，复杂运动任务后，Val/Met 受试者的 MEP 没有显着变化（7%，P = 0.50），而 Met/Met 组的 MEP 有所减少（-38%，P < 0.01）。尽管依赖使用的可塑性存在这些差异，但 BDNF 基因型之间的两种运动任务的表现并没有差异。我们得出的结论是，运动皮层兴奋性的调节受到 BDNF 多态性的强烈影响，在复杂的运动任务中观察到的差异最大。我们还在最罕见的 BDNF 多态性（Met/Met 受试者）中发现了独特的运动皮层可塑性，这可能对这些个体神经系统疾病或损伤后的功能恢复产生影响。
The purpose of this study was to investigate how healthy young subjects with one of three variants of the brain-derived neurotrophic factor (BDNF) gene modulate motor cortex excitability following experimentally induced and use-dependent plasticity interventions. Electromyographic recordings were obtained from the right first dorsal interosseous (FDI) muscle of 12 Val/Val, ten Val/Met and seven Met/Met genotypes (aged 1839 years). Transcranial magnetic stimulation of the left hemisphere was used to assess changes in FDI motor-evoked potentials (MEPs) following three separate interventions involving paired associative stimulation, a simple ballistic task and complex visuomotor tracking task using the index finger. Val/Val subjects increased FDI MEPs following all interventions (= 25%, P < 0.01), whereas the Met allele carriers only showed increased MEPs after the simple motor task (= 26%, P < 0.01). In contrast to the simple motor task, there was no significant change in MEPs for the Val/Met subjects (7%, P = 0.50) and a reduction in MEPs for the Met/Met group (-38%, P < 0.01) following the complex motor task. Despite these differences in use-dependent plasticity, the performance of both motor tasks was not different between BDNF genotypes. We conclude that modulation of motor cortex excitability is strongly influenced by the BDNF polymorphism, with the greatest differences observed for the complex motor task. We also found unique motor cortex plasticity in the rarest form of the BDNF polymorphism (Met/Met subjects), which may have implications for functional recovery after disease or injury to the nervous system in these individuals.