Non Invasive Brain Stimulation Unit, Laboratorio Di Neurologia Clinica E Comportamentale, IRCCS Fondazione S. Lucia, Via Ardeatina, 306, 00179, Rome, Italy.
Department of Psychology, eCampus University, Novedrate, Italy.
Exp Brain Res. 2020 Aug;238(7-8):1677-1684. doi: 10.1007/s00221-020-05844-5. Epub 2020 Jul 23.
Transcranial magnetic stimulation (TMS) based methods are emerging as a unique approach to evaluate in real-time brain electrical activity in healthy and pathological conditions. By applying TMS pulses in two different bran areas within a short temporal frame of few milliseconds, it is possible to investigate their physiological interactions. These paradigms, collectively termed dual-site TMS, have been inspired by Professor John Rothwell's work, based on the idea that applying a conditioning stimulus over a cortical area may activate putative pathways projecting onto a second target area, thus providing a unique opportunity to test the causal effects between interconnected brain areas. This review highlights the most important features of dual-coil TMS protocols, mainly pioneered in Professor John Rothwell's lab. In the first part, I reviewed development of dual-site TMS protocols leading to the discovery of a distributed system of short-latency interactions within the human parieto-frontal network, likely mediated by direct anatomical pathways. In the second part, the physiological role of these dual-site TMS evoked pathways is considered, describing how these functional interactions are not fixed but vary depending on the brain activation, the condition and on the precise time window in which they are explored. Then, I reviewed recent advances showing that the repeated coupling of interconnected neuronal populations, by means of dual-coil TMS, is able to induce spike-time-dependent plasticity and to determine selective potentiation of physiological connectivity between two human brain regions. Finally, the therapeutic implications of these novel discoveries are discussed, pointing to multi-site TMS as a novel tool to identify early features of synaptic dysfunctions, to monitor disease progression and potentially to provide novel therapeutic approaches by reshaping plasticity in different neurological and psychiatric conditions.
经颅磁刺激（TMS）方法正成为一种评估健康和病理状态下大脑电活动的独特方法。通过在几毫秒的短时间内用 TMS 脉冲刺激两个不同的脑区，可以研究它们的生理相互作用。这些被统称为双靶点 TMS 的范式，是基于 John Rothwell 教授的工作提出的，其思想是在皮质区域施加一个刺激可以激活投射到第二个目标区域的假定通路，从而提供了一个独特的机会来测试相互连接的脑区之间的因果关系。这篇综述强调了双线圈 TMS 协议的最重要特征，这些协议主要是由 John Rothwell 教授的实验室首创的。在第一部分中，我回顾了双靶点 TMS 协议的发展，这些协议导致了人类顶-额网络内短潜伏期相互作用分布式系统的发现，这些相互作用可能是通过直接的解剖途径介导的。在第二部分，考虑了这些双靶点 TMS 诱发性通路的生理作用，描述了这些功能相互作用不是固定的，而是取决于大脑的激活状态、条件以及它们被探索的精确时间窗口。然后，我综述了最近的进展，表明通过双线圈 TMS 重复地偶联相互连接的神经元群体，能够诱导尖峰时间依赖性可塑性，并确定两个人类脑区之间的生理连接的选择性增强。最后，讨论了这些新发现的治疗意义，指出多靶点 TMS 是一种识别突触功能障碍早期特征、监测疾病进展并可能通过重塑不同神经和精神疾病状态下的可塑性提供新的治疗方法的新工具。
