Laboratory of Electrophysiology for Translational NeuroScience, Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche, Rome, I-00185 Italy.
GMV, Rome, Italy.
J Neurosci. 2018 Jan 17;38(3):586-594. doi: 10.1523/JNEUROSCI.2521-16.2017. Epub 2017 Dec 1.
In this paper, we pose the following working hypothesis: in humans, transcranial electric stimulation (tES) with a time course that mimics the endogenous activity of its target is capable of altering the target's excitability. In our case, the target was the primary motor cortex (M1). We identified the endogenous neurodynamics of hand M1's subgroups of pyramidal neuronal pools in each of our subjects by applying Functional Source Separation (FSS) to their EEG recordings. We then tested whether the corticospinal excitability of the hand representation under the above described stimulation, which we named transcranial individual neurodynamics stimulation (tIDS), was higher than in the absence of stimulation (baseline). As a check, we compared tIDS with the most efficient noninvasive facilitatory corticospinal tES known so far, which is 20 Hz transcranial alternating current stimulation (tACS). The control conditions were as follows: (1) sham, (2) transcranial random noise stimulation (tRNS) in the same frequency range as tIDS (1-250 Hz), and (3) a low current tIDS (tIDS). Corticospinal excitability was measured with motor-evoked potentials under transcranial magnetic stimulation. The mean motor-evoked potential amplitude increase was 31% of the baseline during tIDS ( < 0.001), and it was 15% during tACS ( = 0.096). tRNS, tIDS, and sham induced no effects. Whereas tACS did not produce an enhancement in any subject at the individual level, tIDS was successful in producing an enhancement in 8 of the 16 subjects. The results of the present proof-of-principle study showed that proper exploitation of local neurodynamics can enhance the efficacy of personalized tES. This study demonstrated that, in humans, transcranial individual neurodynamics stimulation (tIDS), which mimics the endogenous dynamics of the target neuronal pools, effectively changes the excitability of these pools. tIDS holds promise for high-efficacy personalized neuromodulations based on individual local neurodynamics.
在本文中，我们提出了以下工作假设：在人类中，模拟目标内源性活动的时程的经颅电刺激（tES）能够改变目标的兴奋性。在我们的案例中，目标是初级运动皮层（M1）。我们通过将功能源分离（FSS）应用于每个被试者的 EEG 记录，来识别手 M1 的锥体神经元池的内源性神经动力学。然后，我们测试了在上述刺激下，即我们称之为经颅个体神经动力学刺激（tIDS）下，手部代表的皮质脊髓兴奋性是否高于没有刺激（基线）的情况。作为检查，我们将 tIDS 与迄今为止最有效的无创促进皮质脊髓 tES 进行了比较，即 20 Hz 经颅交流电刺激（tACS）。对照条件如下：（1）假刺激，（2）与 tIDS 相同频率范围内的经颅随机噪声刺激（tRNS）（1-250 Hz），以及（3）低电流 tIDS（tIDS）。皮质脊髓兴奋性通过经颅磁刺激下的运动诱发电位进行测量。在 tIDS 期间，运动诱发电位的平均幅度增加了 31%基线（<0.001），在 tACS 期间增加了 15%（=0.096）。tRNS、tIDS 和 sham 没有引起任何影响。虽然 tACS 在个体水平上没有在任何受试者中产生增强作用，但 tIDS 在 16 名受试者中的 8 名中成功产生了增强作用。本原理验证研究的结果表明，适当利用局部神经动力学可以提高个性化 tES 的效果。本研究表明，在人类中，模拟目标神经元池内源性动力学的经颅个体神经动力学刺激（tIDS）有效地改变了这些池的兴奋性。tIDS 有望基于个体局部神经动力学实现高效的个性化神经调节。
