Neuro-physiological adaptations associated with cross-education of strength
Neuro-physiological adaptations associated with cross-education of strength
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DOI：
10.1007/s10548-007-0033-2
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发表时间：
2007-12-01
期刊：
影响因子：
2.7
通讯作者：
Sarty, Gordon E.
中科院分区：
文献类型：
--
作者：
Farthing, Jonathan P.;Borowsky, Ron;Sarty, Gordon E.
力量交叉教育是指对侧同源肢体进行单侧训练后，未训练的对侧肢体力量的增加。我们研究了与力量交叉教育相关的中枢和周围神经适应。二十三名右利手女性被随机分为单侧训练组或意象组。使用功能磁共振成像 (fMRI) 评估八名受试者的子样本（四名训练，四名图像）运动期间的皮质激活模式。力量训练为右臂最大等长尺偏，每周四次，为期六周。在训练之前和之后评估峰值扭矩、肌肉厚度（超声）、激动剂-拮抗剂肌电图（EMG）和fMR1。力量训练对于增加受过训练的四肢（45.3%；P < 0.01）和未经训练的四肢（47.1%；P < 0.01）的力量非常有效。图像组显示任何一只手臂的力量都没有增加。仅训练组受训手臂的肌肉厚度增加（8.4%；P < 0.001）。训练后，未经训练的左臂肌肉收缩时，对侧感觉运动皮层和左颞叶的激活区域扩大（P < 0.001）。与意象组相比，训练与双肢主动肌肌电图的显着变化相关（P < 0.05）。这些结果表明，力量的交叉教育可能部分由感觉运动皮层内的适应控制，这与之前的运动学习研究一致。然而，这项研究表明颞叶区域的参与有助于促进运动的语义记忆，而此前尚未在这方面进行过研究。我们认为颞叶区域可能在力量交叉教育中发挥重要作用。
Cross-education of strength is the increase in strength of the untrained contralateral limb after unilateral training of the opposite homologous limb. We investigated central and peripheral neural adaptations associated with cross-education of strength. Twenty-three right-handed females were randomized into a unilateral training group or an imagery group. A sub-sample of eight subjects (four training, four imagery) was assessed with functional magnetic resonance imaging (fMRI) for patterns of cortical activation during exercise. Strength training was 6 weeks of maximal isometric ulnar deviation of the right arm, four times per week. Peak torque, muscle thickness (ultrasound), agonist-antagonist electromyography (EMG), and fMRl were assessed before and after training. Strength training was highly effective for increasing strength in trained (45.3%; P < 0.01) and untrained (47.1%; P < 0.01) limbs. The imagery group showed no increase in strength for either arm. Muscle thickness increased only in the trained arm of the training group (8.4%; P < 0.001). After training, there was an enlarged region of activation in contralateral sensorimotor cortex and left temporal lobe during muscle contractions with the untrained left arm (P < 0.001). Training was associated with a significantly greater change in agonist muscle EMG pooled over both limbs, compared to the imagery group (P < 0.05). These results suggest that cross-education of strength may be partly controlled by adaptations within sensorimotor cortex, consistent with previous studies of motor learning. However, this research demonstrates the involvement of temporal lobe regions that subserve semantic memory for movement, which has not been previously studied in this context. We argue that temporal lobe regions might play a significant role in the cross-education of strength.