Two-photon Light Field with Neuro-active Sensing for Fast Volumetric Neural Microcircuit Readout

具有神经活性传感的双光子光场，用于快速体积神经微电路读出

• 批准号: BB/R009007/1
• 负责人: Amanda Foust
• 金额: $ 102.88万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FR009007%2F1
• 关键词: Two; photon; Light; Field; Neuro

Underlying our every sensation, thought, memory, decision and action are 100 billion neurons communicating through trillions of electrical impulses each second. Over the past century, neuroscientists have explored brain function on primarily two scales, that of single neurons (i.e., by impaling them with electrodes) and that of entire brain regions (i.e. with electroencephalogram, EEG, and functional magnetic resonance imaging, fMRI). However, between these two scales lies a large knowledge gap surrounding how neurons interact in networks to process and store information, form memories and generate actions. Over the past 10 years, geneticists have developed methods to control and read out brain cell activity with light. They can render neurons sensitive to light to activate or silence them when illuminated with certain wavelengths. In addition, neurons can be made to "glow" or become more fluorescent when active. These "optogenetic" tools make it possible to connect single-neuron properties (i.e., through electrode studies) with functions evolving on the population level (through fMRI and EEG). To achieve this, optical engineers must first overcome a key challenge: the mammalian brain severely scatters and distorts light, resulting in blurry images and thus confusion about which neuron is active. Here we propose to overcome this limitation by utilizing the "optogenetic" ability to activate individual neurons with light in rapid succession. Specifically, we will activate each neuron throughout a brain volume in turn to determine each one's "signature"; that is, the blurry, distorted light pattern it generates when active. We will then use this collection of activity signatures to rapidly and precisely determine which neuron activates and when during subsequent spontaneous activity. We will implement this "collection" approach with a three-dimensional (3D) imaging strategy called "light field." While traditional imaging captures focused images for objects lying in a single plane, "light field" captures perspectives from different angles within a single shapshot. The "light field" approach thus enables us to track neuronal activity simultaneously throughout a volume a brain tissue rather than within a single plane. This novel combination of "light field" imaging with active sensing will significantly increase the speed (10-fold) with which we can track the activity of single neurons throughout a volume. In the near future, development of faster, more sensitive cameras and sensors could increase our instrument's volume capture rates to 100-fold compared to the current state-of-the-art. Moreover, here we will, for the first time, implement "light field imaging" in "two-photon" mode. "Two-photon" is a method to excite fluorescence that is used widely in biomedical research. In contrast to the blue/green wavelengths previously used with "light field," "two-photon" utilizes near-infrared wavelengths that are far less scattered than blue and green, enabling researchers to image deep in scattering tissues. Our new two-photon light field instrument will decrease distortion and thus enable us to image deeper into the brain.By combining targeted neural activation with 3D light-field imaging, we will overcome a key barrier to understanding how neurons interact in networks. With our new instrument, neuroscientists will at last be able to collect data on how neurons work together to process and store information, make decisions and effectuate actions. A detailed understanding of these network-level processes will inform the design of new therapies for neuronal diseases and disorders, such as Alzheimer's, in which these functions are compromised.

在我们的每一种感觉、思想、记忆、决定和行动之下，都有1000亿个神经元每秒通过数万亿个电脉冲进行交流。在过去的一个世纪里，神经科学家主要在两个尺度上探索大脑功能，单个神经元的功能(即通过电极刺穿它们)和整个大脑区域的功能(即脑电、EEG和功能磁共振成像，fMRI)。然而，在这两个尺度之间存在着一个巨大的知识鸿沟，围绕着神经元如何在网络中相互作用来处理和存储信息，形成记忆和产生行动。在过去的10年里，遗传学家已经开发出了用光控制和读出脑细胞活动的方法。它们可以使神经元对光敏感，当受到特定波长的照射时，可以激活或沉默它们。此外，当神经元活动时，可以使其发光或变得更具荧光。这些“光遗传”工具使得将单个神经元的特性(即通过电极研究)与在种群水平上进化的功能(通过功能磁共振成像和脑电)联系起来成为可能。要做到这一点，光学工程师必须首先克服一个关键挑战：哺乳动物的大脑严重散射和扭曲光线，导致图像模糊，从而混淆了哪个神经元是活跃的。在这里，我们建议通过利用光遗传能力来快速连续地激活单个神经元来克服这一限制。具体地说，我们将依次激活整个大脑体积中的每个神经元，以确定每个神经元的“特征”；也就是，当激活时，它产生的模糊、扭曲的光模式。然后，我们将使用这组活动特征来快速准确地确定在随后的自发活动中，哪个神经元被激活，以及何时被激活。我们将使用一种称为“光场”的三维(3D)成像策略来实现这种“集合”方法。传统的成像技术捕捉的是位于同一平面上的物体的聚焦图像，而“光场”技术则是在一张截图中捕捉不同角度的透视图像。因此，“光场”方法使我们能够在整个体积的脑组织中同时跟踪神经元的活动，而不是在一个平面内。这种“光场”成像与主动传感的新组合将显著提高我们跟踪单个神经元在整个体积中的活动的速度(10倍)。在不久的将来，更快、更灵敏的相机和传感器的开发可能会将我们仪器的体积捕获率提高到目前最先进水平的100倍。此外，在这里，我们还将首次实现“双光子”模式下的“光场成像”。“双光子”是一种在生物医学研究中广泛应用的激发荧光的方法。与以前用于“光场”的蓝/绿波长不同，“双光子”利用的近红外波长比蓝和绿的散射要少得多，使研究人员能够在散射组织的深处成像。我们的新双光子光场仪器将减少失真，从而使我们能够更深入大脑进行成像。通过将定向神经激活与3D光场成像相结合，我们将克服理解神经元如何在网络中相互作用的关键障碍。有了我们的新仪器，神经科学家最终将能够收集关于神经元如何协同工作来处理和存储信息、做出决定和实施行动的数据。对这些网络级过程的详细了解将为设计治疗阿尔茨海默氏症等神经元疾病和障碍的新疗法提供信息，在这些疾病和障碍中，这些功能会受到损害。

项目成果

Comparing wide field to 3D light field for imaging red calcium transients in mammalian brain

比较宽视场与 3D 光场对哺乳动物大脑中红色钙瞬变的成像

• DOI: 10.1364/brain.2020.btu2c.4
• 发表时间: 2020
• 作者: Howe C

Subcellular resolution 3D light field imaging with genetically encoded voltage indicators

• DOI: 10.1101/2020.05.22.108191
• 发表时间: 2020-05
• 期刊: bioRxiv
• 作者: Peter Quicke;Carmel L. Howe;P. Song;H. V. Jadan;Chenchen Song;T. Knöpfel;M. Neil;P. Dragotti

Comparing synthetic refocusing to deconvolution for the extraction of neuronal calcium transients from light fields.

比较合成重新聚焦与从光场中提取神经元瞬变的反卷积。

• DOI: 10.1117/1.nph.9.4.041404
• 发表时间: 2022-10
• 期刊: Neurophotonics
• 影响因子: 5.3
• 作者: Howe CL;Quicke P;Song P;Verinaz-Jadan H;Dragotti PL;Foust AJ
• 通讯作者: Foust AJ

All-Optical Methods to Study Neuronal Function

研究神经元功能的全光学方法

• DOI: 10.1007/978-1-0716-2764-8_2
• 发表时间: 2023
• 作者: Quicke P

Voltage imaging reveals the dynamic electrical signatures of human breast cancer cells.

• DOI: 10.1038/s42003-022-04077-2
• 发表时间: 2022-11-11
• 期刊: COMMUNICATIONS BIOLOGY
• 影响因子: 5.9
• 作者: Quicke, Peter;Sun, Yilin;Arias-Garcia, Mar;Beykou, Melina;Acker, Corey D.;Djamgoz, Mustafa B. A.;Bakal, Chris;Foust, Amanda J.
• 通讯作者: Foust, Amanda J.