Interrogating Biophysical Mechanisms of Magnetogenetic Cell Stimulation at Radio Frequencies

摘要 磁遗传学是最近提出的使用电磁场刺激细胞的方法。在一个 在一种方法中，施加射频（RF）电磁场以刺激膜通道蛋白， TRPV 1和TRPV 4与铁蛋白结合。这个概念非常有吸引力，因为它使无线神经网络 刺激，而不限制穿透深度或侵入性手术的要求。如果成功，RF- 基于磁遗传学的方法可以为大规模神经刺激提供一种非侵入性方法， 在大脑的任何地方，并实现细胞特异性。这种能力克服了在其它实施例中的显著限制。 例如电刺激和光遗传学技术，其中刺激在空间上受到限制。然而，在这方面， 虽然已经有几个独立的报告，实验证据的磁效应，使用 射频波，这种影响的物理和神经生物学基础仍然不清楚和有争议。 报道的实验仅在少数选定的频率和振幅下进行， 响应大多是基于下游生理效应间接测量的。的目的 拟议的项目是系统地表征，建模和验证神经生物学和细胞反应 在表达铁蛋白连接的TRPV 1和TRPV 4通道的神经元中的RF刺激后。具体来说，我们的目标是 以表征这些磁通道的：1）神经元对电刺激和化学刺激的反应 以及在宽范围的频率和振幅上的RF刺激; 2）对RF的温度响应 蛋白质、细胞质膜和细胞水平的刺激; 3）RF后的细胞代谢过程 刺激.我们将系统地评估潜在机制的两个新的工作假设。如果 成功后，该项目将表征细胞对射频刺激的反应，量化激活阈值， 和安全限度，建立标准协议，并阐明生物物理基础，这一报告的RF- 基于磁致现象。它将解决推进这项技术的一个根本挑战， 指导更合理的设计和技术改进。了解初始的机制 磁遗传学的报告将是对目前神经刺激整体的重要补充， 技术，如电刺激和光遗传学，并有助于大脑的一个中心目标 该倡议旨在开发适用于控制特定细胞的新的和改进的扰动技术 调节中枢神经系统功能的类型和回路。

Abstract Magnetogenetics is a recently proposed method for stimulating cells using electromagnetic fields. In one approach, radio-frequency (RF) electromagnetic fields are applied to stimulate membrane channel proteins such as TRPV1 and TRPV4 that are attached to ferritins. The concept is highly attractive as it enables wireless neural stimulation without limitation on penetration depth or the requirement of invasive surgeries. If successful, RF- based magnetogenetics can provide a non-invasive approach for large-scale neural stimulation that can reach anywhere in the brain and achieve cellular specificity. This capability overcomes a significant limitation in other techniques such as electrical stimulation and optogenetics where stimulation is spatially restricted. However, while there have been several independent reports of experimental evidences for magnetogenetic effects using RF waves, the physical and neurobiological underpinnings of such effects remain unclear and controversial. Reported experiments have been conducted only in a few selected frequencies and amplitudes and the responses were mostly measured indirectly based on downstream physiological effects. The objective of the proposed project is to systematically characterize, model and validate the neurobiological and cellular responses upon RF stimulation in neurons expressing ferritin-attached TRPV1 and TRPV4 channels. Specifically, we aim to characterize these magnetogenetic channels of their: 1) neuronal responses to electrical and chemical stimuli and to RF stimulation over a wide range of frequencies and amplitudes; 2) temperature responses to RF stimulation at the protein, cytoplasmic membrane and cellular level; 3) cellular metabolic processes upon RF stimulation. We will systematically evaluate two novel working hypotheses of the underlying mechanisms. If successful, the project will characterize the cellular responses to RF stimulation, quantify activation thresholds and safety limits, establish standard protocols and elucidate the biophysical underpinnings of this reported RF- based magnetogenetic phenomenon. It would resolve a fundamental challenge in advancing this technology and guide a more rationale design and improvement of the techniques. Understanding the mechanisms of the initial reports of magnetogenetics would be a significant addition to the present ensemble of neuro-stimulation technologies such as electrical stimulation and optogenetics and contribute to one central goal of the BRAIN Initiative that is to develop new and improved perturbation technologies suitable for controlling specified cell types and circuits to modulate function in the central nervous system.