Anil Swathi, Lu Han, Rotter Stefan, Vlachos Andreas
Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.
bioRxiv. 2023 Mar 21:2023.03.20.533396. doi: 10.1101/2023.03.20.533396.
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique used to induce neuronal plasticity in healthy individuals and patients. Designing effective and reproducible rTMS protocols poses a major challenge in the field as the underlying biomechanisms remain elusive. Current clinical protocol designs are often based on studies reporting rTMS-induced long-term potentiation or depression of synaptic transmission. Herein, we employed computational modeling to explore the effects of rTMS on long-term structural plasticity and changes in network connectivity. We simulated a recurrent neuronal network with homeostatic structural plasticity between excitatory neurons, and demonstrated that this mechanism was sensitive to specific parameters of the stimulation protocol (i.e., frequency, intensity, and duration of stimulation). The feedback-inhibition initiated by network stimulation influenced the net stimulation outcome and hindered the rTMS-induced homeostatic structural plasticity, highlighting the role of inhibitory networks. These findings suggest a novel mechanism for the lasting effects of rTMS, i.e., rTMS-induced homeostatic structural plasticity, and highlight the importance of network inhibition in careful protocol design, standardization, and optimization of stimulation.
重复经颅磁刺激(rTMS)是一种非侵入性脑刺激技术,用于在健康个体和患者中诱导神经元可塑性。由于潜在的生物力学机制仍然难以捉摸,设计有效且可重复的rTMS方案是该领域的一项重大挑战。当前的临床方案设计通常基于报告rTMS诱导的突触传递长期增强或抑制的研究。在此,我们采用计算建模来探索rTMS对长期结构可塑性和网络连接变化的影响。我们模拟了一个在兴奋性神经元之间具有稳态结构可塑性的递归神经元网络,并证明该机制对刺激方案的特定参数(即刺激频率、强度和持续时间)敏感。网络刺激引发的反馈抑制影响了净刺激结果,并阻碍了rTMS诱导的稳态结构可塑性,突出了抑制性网络的作用。这些发现揭示了rTMS持久效应的一种新机制,即rTMS诱导的稳态结构可塑性,并强调了网络抑制在精心设计方案、标准化和优化刺激方面的重要性。
Front Neural Circuits. 2016-11-28