Yoshikawa Takahiro, Tateno Takashi
Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan.
Division of Bioengineering and Bioinformatics, Faculty of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan
eNeuro. 2025 May 14;12(5). doi: 10.1523/ENEURO.0577-24.2025. Print 2025 May.
Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method that has been used to treat various brain disorders. The modulatory effects of rTMS can be adjusted by changing the repetition patterns. Theta-burst magnetic stimulation (TBS) is a magnetic stimulation pattern that can induce long-lasting modulatory effects with a short stimulation period. However, its effects on auditory brain regions remain unclear because of a lack of animal studies in which invasive techniques allow for a detailed exploration of the underlying neural mechanisms. In the current study, we investigated the effects of TBS on the C57BL/6J mouse auditory cortex using a custom-built 7 mm magnetic stimulation coil. Extracellular recordings were made before, during, and after the application of intermittent TBS (iTBS), continuous TBS (cTBS), or sham stimulation. Local field potential amplitudes were increased for 5-20 min post-iTBS compared with the sham condition and were decreased at 10 min post-cTBS compared with the sham condition. The bidirectional modulatory effects observed in our study are consistent with previous findings from other brain regions. Additionally, multiunit activities were significantly altered in cortical layers 2/3 and 4 but not layer 5, indicating that the modulatory effects were localized to the surface region of the auditory cortex. Interestingly, in the iTBS group, the amplitude of average spike waveforms increased with a 15 min delay. Our findings provide physiological evidence of TBS modulation of the rodent auditory cortex and may guide future research seeking to optimize rTMS for modulating hearing abilities.
重复经颅磁刺激（rTMS）是一种已被用于治疗各种脑部疾病的非侵入性方法。rTMS的调节作用可通过改变重复模式来调整。theta爆发式磁刺激（TBS）是一种磁刺激模式，能在短刺激期内诱导持久的调节作用。然而，由于缺乏动物研究，其对听觉脑区的影响仍不清楚，在动物研究中，侵入性技术可用于详细探究潜在的神经机制。在本研究中，我们使用定制的7毫米磁刺激线圈，研究了TBS对C57BL/6J小鼠听觉皮层的影响。在施加间歇性TBS（iTBS）、连续性TBS（cTBS）或假刺激之前、期间和之后进行细胞外记录。与假刺激条件相比，iTBS后局部场电位振幅在5 - 20分钟内升高，cTBS后10分钟时与假刺激条件相比降低。我们研究中观察到的双向调节作用与先前在其他脑区的研究结果一致。此外，第2/3层和第4层皮质中的多单位活动显著改变，但第5层未改变，表明调节作用局限于听觉皮层的表面区域。有趣的是，在iTBS组中，平均峰电位波形的振幅在延迟15分钟时增加。我们的研究结果为TBS对啮齿动物听觉皮层的调节提供了生理学证据，并可能指导未来旨在优化rTMS以调节听力能力的研究。
