Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; International Graduate School of Neuroscience, IGSN, Ruhr University Bochum, Bochum, Germany.
Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany.
Brain Stimul. 2020 Jul-Aug;13(4):987-997. doi: 10.1016/j.brs.2020.04.009. Epub 2020 Apr 21.
A single session of anodal tDCS induces LTP-like plasticity which lasts for about 1 h, while repetition of stimulation within a time interval of 30 min results in late-phase effects lasting for at least 24 h with standard stimulation protocols.
In this pilot study, we explored if the after-effects of a recently developed intensified single session stimulation protocol are relevantly prolonged in the motor cortex by repetition of this intervention.
16 healthy right-handed subjects participated in this study. The effects of an intensified (3 mA-20min) and a standard anodal tDCS protocol (1 mA-15min) with short (20 min) and long (3 h) repetition intervals were compared with the effects of respective single session tDCS protocols (3 mA-20min, 1 mA-15min, and Sham). Cortical excitability alterations were monitored by single-pulse TMS-elicited MEPs.
Compared to sham, both single session tDCS protocols (1 mA-15min, and 3 mA-20min) resulted in cortical excitability enhancements lasting for about 30 min after stimulation. The short repetition interval (20 min) resulted in a prolongation of after-effects for the standard protocol, which lasted for more than 24 h after stimulation. For the intensified protocol, the prolongation of after-effects was limited to 120 min after stimulation. The long repetition interval (3 h) resulted in no excitability-enhancing after-effects for the intensified, and only minor excitability enhancement within the first 30 min after the intervention for the standard protocol.
These results suggest a non-linearity of late-phase LTP-like plasticity induction, which was dependent not only on the interval of intervention repetition, but also on other protocol characteristics, including intensity, and duration of tDCS. Further studies in larger samples are needed to confirm these results.
单次阳极经颅直流电刺激（anodal tDCS）诱导类似长时程增强（LTP）的可塑性，持续约 1 小时，而在 30 分钟的时间间隔内重复刺激会导致至少持续 24 小时的晚期效应，使用标准刺激方案。
在这项初步研究中，我们探讨了最近开发的强化单次刺激方案的后效是否通过重复这种干预而在运动皮层中得到显著延长。
16 名健康的右利手受试者参与了这项研究。比较了强化（3 mA-20 分钟）和标准阳极 tDCS 方案（1 mA-15 分钟）的短（20 分钟）和长（3 小时）重复间隔的效果，以及各自的单次 tDCS 方案（3 mA-20 分钟、1 mA-15 分钟和假刺激）的效果。通过单脉冲经颅磁刺激（TMS）诱发的运动诱发电位（MEPs）监测皮质兴奋性变化。
与假刺激相比，两种单次刺激方案（1 mA-15 分钟和 3 mA-20 分钟）均导致刺激后约 30 分钟皮质兴奋性增强。短重复间隔（20 分钟）导致标准方案的后效延长，刺激后持续时间超过 24 小时。对于强化方案，后效的延长仅限于刺激后 120 分钟。长重复间隔（3 小时）导致强化方案无兴奋性增强后的效应，而标准方案仅在干预后 30 分钟内引起轻微的兴奋性增强。
这些结果表明晚期类似长时程增强可塑性诱导的非线性，这不仅取决于干预重复的间隔，还取决于其他方案特征，包括 tDCS 的强度和持续时间。需要更大样本的进一步研究来证实这些结果。
