The influence of sensory afferent input on local motor cortical excitatory circuitry in humans
The influence of sensory afferent input on local motor cortical excitatory circuitry in humans
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DOI：
10.1113/jphysiol.2014.286245
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发表时间：
2015-04-01
影响因子：
5.5
通讯作者：
Chen, Robert
中科院分区：
文献类型：
--
作者：
Cash, Robin F. H.;Isayama, Reina;Chen, Robert
在人类中，感觉运动整合可以通过结合感觉输入和经颅磁刺激（TMS）来研究。短潜伏期传入抑制（SAI）是指正中神经刺激后20-25ms的运动皮质抑制。我们研究了SAI与短间隔皮层内促进（SICF）之间的相互作用，这是一种兴奋性运动皮层回路。共进行了7次实验。与预期相反，SICF在SAI （SICFSAI）在场的情况下得到了促进。这种效应是SICF特有的，因为当SICF不存在时，在SICF槽1处没有效应。此外，随着SICF或SAI的增强，促进性SICFSAI相互作用增强。SAI和SICF在个体间存在相关性，且当SICF在SAI存在的情况下传递时，这种关系得以维持，表明SAI和SICF在感觉运动整合中存在内在关系。这种相互作用存在于静息和肌肉收缩期间，具有广泛的体位影响，并存在于由前后电流方向和前后电流方向诱导的不同神经元间SICF回路中。我们的结果与从感觉皮层到运动皮层的投射终止于被认为起源于晚期间接（I-）波的浅层，以及对锥体输出有更直接影响的深层的发现是一致的。这种相互作用可能与感觉运动整合和运动控制有关。
In human, sensorimotor integration can be investigated by combining sensory input and transcranial magnetic stimulation (TMS). Short latency afferent inhibition (SAI) refers to motor cortical inhibition 20-25ms after median nerve stimulation. We investigated the interaction between SAI and short-interval intracortical facilitation (SICF), an excitatory motor cortical circuit. Seven experiments were performed. Contrary to expectations, SICF was facilitated in the presence of SAI (SICFSAI). This effect is specific to SICF since there was no effect at SICF trough 1 when SICF was absent. Furthermore, the facilitatory SICFSAI interaction increased with stronger SICF or SAI. SAI and SICF correlated between individuals, and this relationship was maintained when SICF was delivered in the presence of SAI, suggesting an intrinsic relationship between SAI and SICF in sensorimotor integration. The interaction was present at rest and during muscle contraction, had a broad degree of somatotopic influence and was present in different interneuronal SICF circuits induced by posterior-anterior and anterior-posterior current directions. Our results are compatible with the finding that projections from sensory to motor cortex terminate in both superficial layers where late indirect (I-) waves are thought to originate, as well as deeper layers with more direct effect on pyramidal output. This interaction is likely to be relevant to sensorimotor integration and motor control.