Targeted Neuromodulation by Nanosecond Pulsed Electric Fields

纳秒脉冲电场是一种新型的神经调节方式，具有独特的功能 与传统的电刺激有质的不同。NsPEF的潜在优势包括 不限于很少或没有电化学副作用的长时间刺激；低阈值激发； 基于电池充电时间常数的选择性；在刺激、抑制和 消融；以及非侵入性地实现这些效果，无论是用于门诊深部脑刺激还是用于肿瘤 消融。 NsPEF的主要作用是迅速建立细胞膜电位(MP)。实时测量 MP动力学的变化是预测nsPEF刺激结果的关键。它们也是理解 双极抵消，这是一种独特的功能，可以实现nsPEF的非侵入性干扰靶向 神经调节。然而，nsPEF的膜充电发生在纳秒时间尺度上，速度要快得多 而不是现有的电生理和成像方法所能解决的。 我们已经通过实施用于MP成像的选通脉冲激光显微镜来应对这一挑战 精度优于50 ns。在这种独一无二的装置中，加载了快速电压敏感荧光的细胞 染料被暴露在高功率瞬时激光闪光(5kW，6 ns)下。闪光是动态的 与靶细胞的nsPEF刺激同步。在不同时间拍摄的荧光照片和 在nsPEF显示MP变化的实时动态以及这些变化如何在下游达到顶峰之后 这些效应包括开放电压门控离子通道、启动动作电位和纳米电穿孔。 我们将使用这种全新的设置来理解神经元如何响应的精细机制和原理 到纳秒的电应力。我们将描述唤醒所需的nsPEF参数 神经调节效应并调整干扰靶向方案以在远离 刺激电极。我们将对电场阈值进行有限元建模，并使用我们的In 体外结果，以确定非侵入性脑深部刺激的可行性和nsPEF要求。 这个项目将产生关于神经元功能的新的基本知识，包括纳秒尺度 细胞膜和离子通道的生物物理学。我们将系统地描述nsPEF神经调节 影响并将其与神经元的介电和生理特性以及nsPEF刺激联系起来 参数。这一体外项目将利用R21“高风险、高回报”的理念，收集机械和 动物和人类研究nsPEF神经调节所需的定量数据。

Nanosecond pulsed electric field (nsPEF) is a new modality for neuromodulation, with unique capabilities qualitatively different from the conventional electrostimulation. The potential benefits of nsPEF include but are not limited to prolonged stimulation with little or no electrochemical side effects; excitation at lower thresholds; selectivity based on cell charging time constant; the capability of choosing between stimulation, inhibition, and ablation; and achieving these effects non-invasively, either for outpatient deep brain stimulation or for tumor ablation. The primary effect of nsPEF is a rapid build-up of cell membrane potential (MP). Real-time measurements of MP kinetics are a key to predicting the outcomes of nsPEF stimulation. They are also a key to understanding bipolar cancellation, a unique feature that enables interference targeting of nsPEF for non-invasive neuromodulation. However, membrane charging by nsPEF occurs on a nanosecond time scale, much faster than could be resolved by the existing electrophysiological and imaging methods. We have addressed this challenge by implementing strobe pulsed laser microscopy for MP imaging with better than 50 ns accuracy. In this one-of-a-kind set-up, cells loaded with a fast voltage-sensitive fluorescence dye are exposed to high-power momentary laser flashes (5 kW, 6 ns). The flashes are dynamically synchronized with nsPEF stimulation of target cells. Photos of fluorescence taken at different times during and after nsPEF show the real-time dynamics of MP changes and how these changes culminate in downstream effects, such as opening of voltage gated ion channels, initiation of action potentials, and nanoelectroporation. We will employ this all-new set-up for understanding fine mechanisms and principles how neurons respond to the nanosecond electric stress. We will characterize nsPEF parameters needed to evoke the desired neuromodulation effect and tune the interference targeting protocols to achieve this effect at a distance from stimulating electrodes. We will perform finite element modeling of the electric field thresholds and use our in vitro results to define the feasibility and nsPEF requirements for non-invasive deep brain stimulation. This project will generate new basic knowledge of neuronal function, including nanosecond-scale biophysics of the cell membrane and ion channels. We will systematically characterize nsPEF neuromodulation effects and link them to dielectric and physiological properties of neurons and to nsPEF stimulation parameters. This in vitro project will utilize R21 “high risk, high reward” concept to collect mechanistic and quantitative data necessary for animal and human studies of nsPEF neuromodulation.