Non-invasive stimulation of deep brain regions has been a major goal for neuroscience and neuromodulation in the past three decades. Transcranial magnetic stimulation (TMS), for instance, cannot target deep regions in the brain without activating the overlying tissues and has a poor spatial resolution. In this manuscript, we propose a new concept that relies on the temporal interference of two high-frequency magnetic fields generated by two electromagnetic solenoids. To illustrate the concept, custom solenoids were fabricated and optimized to generate temporal interfering electric fields for rodent brain stimulation. C-Fos expression was used to track neuronal activation. C-Fos expression was not present in regions impacted by only one high-frequency magnetic field indicating ineffective recruitment of neural activity in non-target regions. In contrast, regions impacted by two fields that interfere to create a low-frequency envelope display a strong increase in c-Fos expression. Therefore, this magnetic temporal interference solenoid-based system provides a framework to perform further stimulation studies that would investigate the advantages it could bring over conventional TMS systems.

中文翻译：

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无创局灶性脑刺激的磁时间干扰

在过去的三十年里，对深部大脑区域的非侵入性刺激一直是神经科学和神经调节的主要目标。例如，经颅磁刺激 (TMS) 无法在不激活覆盖组织的情况下靶向大脑深层区域，并且空间分辨率较差。在这份手稿中，我们提出了一个新概念，该概念依赖于两个电磁螺线管产生的两个高频磁场的时间干扰。为了说明这一概念，制造并优化了定制螺线管，以产生用于啮齿动物大脑刺激的时间干扰电场。C-Fos 表达用于跟踪神经元激活。在仅受一个高频磁场影响的区域中不存在 C-Fos 表达，表明在非目标区域中神经活动的募集无效。相比之下，受两个干扰产生低频包络的场影响的区域显示出 c-Fos 表达的强烈增加。因此，这种基于磁时间干扰螺线管的系统提供了一个框架来进行进一步的刺激研究，以研究它可以带来的传统 TMS 系统的优势。