Corticospinal excitability and somatosensory information processing of the lower limb muscle during upper limb voluntary or electrically induced muscle contractions
Corticospinal excitability and somatosensory information processing of the lower limb muscle during upper limb voluntary or electrically induced muscle contractions
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DOI：
10.1111/ejn.15643
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发表时间：
2022-03-27
影响因子：
3.4
通讯作者：
Nakazawa, Kimitaka
中科院分区：
文献类型：
--
作者：
Kato, Tatsuya;Kaneko, Naotsugu;Nakazawa, Kimitaka
上肢和下肢之间的神经相互作用是人类运动协调的基础。具体来说，上肢随意肌收缩可以促进下肢肌肉的脊髓和皮质脊髓兴奋性。然而，关于躯体感觉信息在胳膊-腿神经相互作用中的参与，我们所知甚少。在这里，我们研究了自愿腕屈和电诱导腕屈对下肢皮质脊髓兴奋性和体感觉信息加工的影响。在实验1中，我们测量了经颅磁刺激（TMS）诱发的运动诱发电位（MEPs）在静息比目鱼肌（SOL）静息或在自主或神经肌肉电刺激（NMES）诱导的手腕屈曲。腕屈曲力与最大自主收缩力（MVC）的10%相匹配。我们发现，与其他情况相比，在自愿腕关节屈曲期间，SOL MEPs显著增加，而非nmes诱导的腕关节屈曲（P < 0.001）。在实验2中，我们检测了相同条件下胫骨神经刺激后的体感诱发电位（SEPs）。结果显示，自发性腕关节屈曲和nmes诱导的腕关节屈曲期间，sep均未发生变化。在实验3中，我们检测了10%、20%和30% MVC腕关节自愿屈曲时sep的调制。在30% MVC腕关节自愿屈曲时，P50-N70 SEP成分明显减弱（P = 0.003）。我们的研究结果表明，nmes诱导的上肢肌肉收缩产生的体感信息可能对下肢皮质脊髓兴奋性和体感信息加工有有限的影响。然而，随意腕屈曲通过运动区调节了皮质脊髓兴奋性和下肢的体感信息加工。
Neural interactions between upper and lower limbs underlie motor coordination in humans. Specifically, upper limb voluntary muscle contraction can facilitate spinal and corticospinal excitability of the lower limb muscles. However, little remains known on the involvement of somatosensory information in arm-leg neural interactions. Here, we investigated effects of voluntary and electrically induced wrist flexion on corticospinal excitability and somatosensory information processing of the lower limbs. In Experiment 1, we measured transcranial magnetic stimulation (TMS)-evoked motor evoked potentials (MEPs) of the resting soleus (SOL) muscle at rest or during voluntary or neuromuscular electrical stimulation (NMES)-induced wrist flexion. The wrist flexion force was matched to 10% of the maximum voluntary contraction (MVC). We found that SOL MEPs were significantly increased during voluntary, but not NMES-induced, wrist flexion, compared to the rest (P < .001). In Experiment 2, we examined somatosensory evoked potentials (SEPs) following tibial nerve stimulation under the same conditions. The results showed that SEPs were unchanged during both voluntary and NMES-induced wrist flexion. In Experiment 3, we examined the modulation of SEPs during 10%, 20% and 30% MVC voluntary wrist flexion. During 30% MVC voluntary wrist flexion, P50-N70 SEP component was significantly attenuated compared to the rest (P = .003). Our results propose that the somatosensory information generated by NMES-induced upper limb muscle contractions may have a limited effect on corticospinal excitability and somatosensory information processing of the lower limbs. However, voluntary wrist flexion modulated corticospinal excitability and somatosensory information processing of the lower limbs via motor areas.