Sonoelectric tomography (SET): High-resolution noninvasive neuronal current tomography

声电断层扫描 (SET)：高分辨率无创神经元电流断层扫描

• 批准号: 9037285
• 负责人: MATTI HAMALAINEN
• 金额: $ 48.03万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-23 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9037285
• 关键词: Active Sites; Adult; Animals; Area; Brain; Brain Mapping; Brain Stem; Code; Digit structure; Electric Capacitance; Electroencephalography; Fingers; Focused Ultrasound; Frequencies; Hand; Head; Human; Human Volunteers; Image; Imaging technology; Lateral; Lead; Location; Maps; Measures; Mechanics; Membrane; Methods; Neocortex; Neurons; Noise; Physiologic pulse; Preparation; Property; Protocols documentation; Rattus; Resolution; Safety; Scalp structure; Scheme; Series; Signal Transduction; Site; Solutions; Source; Structure; Surface; System; Techniques; Testing; Time; Tissues; Transcutaneous Electric Nerve Stimulation; Ultrasonography; Validation; Vibrissae; Width; barrel cortex; base; electrical potential; extracellular; human study; imaging modality; in vivo; indexing; millimeter; millisecond; next generation; novel; novel strategies; pressure; public health relevance; tomography; vibration; voltage

 DESCRIPTION (provided by applicant): Presently there is no imaging technology capable of detecting neuronal activity in the entire human brain with millisecond and millimeter resolution. We propose to evaluate the possibility of developing a novel noninvasive method, sonoelectric tomography (SET), capable of directly imaging electrophysiological activity in the entire human brain with such resolution. In this method, conventional scalp electroencephalography (EEG) is used to measure the electrical activity. Each location of active tissue giving rise to the EEG signals is determined from the tagged US signature in the EEG signals. This information can be used to noninvasively construct a tomographic image of neuronal currents. In order to develop such a technique, we will evaluate three candidate mechanisms: (1) acousto-electric (AE) modulation of tissue resistivity, (2) mechanical vibration of the equivalent current dipole sources in active tissue, and (3) modulation of membrane properties. At present, it is still unknown which of these mechanisms can be used to implement the SET. We will first evaluate these mechanisms in rats in vivo. In Aim 1, we will apply a focused US to one region of the barrel cortex of the rat and test the sensitivity of the SET based on each mechanism. One barrel column will be activated by single whisker stimulation and the resulting local field potentials (LFPs) on the brain or scalp will be analyzed. The most viable US-encoding scheme will be determined from the US signatures in the LFPs. Aim 2 will be very similar to Aim 1, except a single linear US beam varying in US frequency along the beam will be applied to produce a one-dimensional image of neuronal activity. Aims 1 and 2 will establish the effective and safe mechanism for developing SET for human use. In Aim 3, the five digits of a hand will be stimulated with transcutaneous electrical stimulation to activate the finger areas in areas 3b. A linear US beam will be applied to each projection area in area 3b. The scalp EEG signals in area 3b will be analyzed for presence of EEG signals at the US frequency specific for each projection site. This will identify each active site. We will test to see if this method can identiy multiple active tissues. Alternatively, we will first identify the active tissues using a whole-hea MEG and/or EEG and then use the US to test the presence of activity at each predicted site. These tests will determine the feasibility and the best direction for developing a truly whole-brai US-based Activity mapping (USAmapping) technique.

 描述（由申请人提供）：目前还没有能够以毫秒和毫米分辨率检测整个人脑神经活动的成像技术，我们建议评估开发一种新型非侵入性方法——声电断层扫描（SET）的可能性。以这种分辨率直接对整个人脑的电生理活动进行成像在这种方法中，使用传统的头皮脑电图（EEG）来测量产生脑电图信号的活动组织的每个位置。该信息可用于无创地构建神经电流的断层扫描图像。为了开发这种技术，我们将评估三种候选机制：（1）声电（AE）。组织电阻率的调制，(2) 等效电流偶极子源的机械振动 (3) 膜特性的调节 目前，尚不清楚这些机制中的哪一个可用于实现 SET，我们将首先在大鼠体内评估这些机制。对大鼠桶状皮层的一个区域进行聚焦超声，并根据每种机制测试 SET 的灵敏度，单个胡须刺激将激活一个桶状柱，从而在大脑或头皮上产生局部场电位 (LFP)。进行分析最可行。 US 编码方案将根据 LFP 中的 US 签名确定，目标 2 与目标 1 非常相似，除了将应用沿波束变化的 US 频率的单个线性 US 波束来生成一维神经图像。目标 1 和 2 将建立有效且安全的机制来开发供人类使用的 SET。 在目标 3 中，将通过经皮电刺激来刺激手的五个手指，以激活手指区域。 3b.将向区域 3b 中的每个投影区域应用线性 US 波束，分析区域 3b 中是否存在特定于每个投影部位的 US 频率的 EEG 信号。我们将测试该方法是否可以识别多个活性组织，或者，我们将首先使用全头 MEG 和/或 EEG 来识别活性组织，然后使用 US 来测试每个预测部位是否存在活动。将确定可行性以及开发真正的全脑美国活动映射（USAmapping）技术的最佳方向。