BRAIN EAGER: Wireless Measurement of Neuronal Currents Using Spin-Torque Nano-Oscillators

该奖项是由生物科学局(BIO)的两个项目-生物研究仪器开发计划(IDBR)和新兴前沿(EF)-联合颁发的。大脑是一个相互连接的复杂电路网络，以动作电位的形式交换信号。这些动作电位是理解认知和复杂思维的关键。现有的非侵入性探测神经元活动的方法不能达到足够的空间或时间分辨率来观察单个神经元或小簇的个体动作电位，这是一个主要的限制。这位首席研究员建议研究一种新的非侵入性测量方法，这种方法将能够读出整个大脑的个体动作电位。该项目将利用自旋电子器件的最新进展来创造可注射的纳米记者，这种记者将检测大脑中的微弱电信号，并将其转换为可以在体外无线检测到的微波信号。将要使用的检测设备是自旋扭矩纳米振荡器(STNO)，它将电信号转换为可以无线检测的微波场振荡。这种方法最终可能导致第一种非侵入性技术，能够测量活的灵长类动物和人类中单个神经元和小规模神经元网络的激活。这种能力将对我们理解大脑和认知的内部运作产生重大影响。它还可能有重要的临床应用，特别是在神经疾病和脑机接口领域。在细胞水平上非侵入性监测神经元活动的能力对于更好地理解认知以及许多临床应用是至关重要的。目前，所有非侵入性监测大脑活动的方法都不能同时达到从单个神经元感知个体动作电位所需的空间和时间分辨率。该项目是一种非侵入性测量的新方法，将能够从单个神经元读出整个大脑的单个动作电位。为了实现将电活动转化为微波，将使用一种名为自旋扭矩纳米振荡器(STNO)的纳米设备，将稳定的电信号转换为可以无线检测的微波频率磁场振荡。STNO对电信号的反应是微秒级的，因此可以直接用于测量单个神经元的动作电位。此外，STNO是一个纳米级的设备，可以报告单个神经元的放电和位置。该项目代表了自旋电子学这一令人兴奋和快速发展的领域在神经生物学中的第一次应用。将开发一种测试系统，其中包括神经元模拟器(模拟单个神经元的电压和阻抗的可调电路)和高灵敏度微波接收器，以演示这些设备无线报告神经元激活状态的能力。该项目还涉及神经生物学应用的STNO器件的设计、制造和测试优化。这个急切的项目的最终和具体目标是在活的鱿鱼轴突上对所提议的装置进行概念验证演示。

This award is jointly made by two programs the Instrument Development for Biological Research program (IDBR) and Emerging Frontiers (EF) in the Directorate of Biological Sciences (BIO).The brain is a complex network of interconnected circuits that exchange signals in the form of action potentials. These action potentials hold the key to understanding cognition and complex thought. Currently available non-invasive methods for probing neuronal activity cannot achieve sufficient spatial or temporal resolution to observe individual action potentials from single neurons or small clusters, which is a major limitation. This principal investigator proposes to study a novel approach for non-invasive measurements that will be able to read out individual action potentials across the entire brain. This project will take advantage of recent advances in spintronic devices to create injectable nano-reporters that will detect weak electrical signals in the brain and convert them to microwave signals that can be detected wirelessly outside the body. The detection device to be used is the spin-torque nano-oscillator (STNO), which converts electrical signals into microwave field oscillations that can be detected wirelessly. This approach could ultimately lead to the first non-invasive technology capable of measuring activations of individual neurons and small-scale neuronal networks in live primates and humans. This capability would have a major impact on our understanding of the inner workings of the brain and cognition. It could also have important clinical applications, particularly in the areas of neurological disorders and brain machine interfaces. The ability to monitor neuronal activity at the cellular level non-invasively is crucial for attaining a better understanding of cognition, as well as many clinical applications. Currently, all non-invasive methods for monitoring brain activity cannot simultaneously achieve the spatial and temporal resolution required to sense individual action potentials from a single neuron. This project is a novel approach for non-invasive measurements that will be able to read out individual action potentials across the whole brain from single neurons. To achieve the transduction of electrical activity to microwaves, a nano-sized device called a spin-torque nano-oscillator (STNO) will be used that converts steady electrical signals into microwave frequency magnetic field oscillations that can be detected wirelessly. The STNO responds in microseconds to electric signals, and thus can be directly used to measure individual neuronal action potentials. In addition, the STNO is a nano-scale device and can report on the firing and location of a single neuron. This project represents the first application to neurobiology of the exciting and rapidly evolving field of spintronics. A test system will be developed that includes a neuron simulator (a tunable circuit that simulates the voltages and impedance of a single neuron) and a high sensitivity microwave receiver to demonstrate the ability of these devices to report that activation state of a neuron wirelessly. this project also involves the design, fabrication, and test optimization of STNO devices for neurobiological applications. The ultimate and specific goal of this EAGER project is to perform a proof-of-concept demonstration of the proposed apparatus on a live squid axon.