Enhanced Optogenetic Control of Neuronal Activity with Tailored Light Stimuli

提案编号：1403660P.I.：Boppart，Stephen A.标题：利用定制的光刺激增强神经元活动的光遗传控制非技术解释意义：该项目将研究新形式的光如何增强电输出和对已转基因为光敏感神经元的控制。光遗传学是一个快速发展的领域，它使用分子生物学技术使细胞功能能够用光来控制。当神经元(神经细胞)经过基因改造以表达光激活的膜通道时，它们可以在暴露在光中时触发电活动。这种光激活控制神经元活动的新水平尚未得到充分利用，但它为理解神经元及其电路如何在大脑中发挥作用以形成思想、记忆、行为和情绪提供了新的机会。在光学科学和工程中，现在的进步使产生具有定制属性的各种新形式的光，或所谓的定制光成为可能。本研究对神经科学和生物光子学领域具有重要意义。生物光子学是研究光如何与生物细胞和组织相互作用的科学，神经科学家试图了解大脑和思维是如何工作的。这个项目中用于产生定制光的新光源将改变我们使用光遗传学来研究和理解神经元、神经回路和大脑功能的方式。该项目也是高度跨学科的，将为本科生和研究生提供一个独特的教育和培训机会，帮助他们解决未来工程学和生物学中复杂的跨学科问题。这项研究的结果也将被整合到生物光子学、神经科学和高级显微镜的本科生和研究生课程中。这项研究的长期社会效益将包括提高公众的科学素养，了解我们大脑中的神经元和神经电路是如何工作的，以及如何使用新型的光和激光来探测我们大脑的复杂功能。技术说明光遗传学是一个迅速扩展的领域，它起源于神经科学领域，对哺乳动物神经元的基因改造使能够对膜通道进行光激活控制，从而引发动作电位。虽然这一概念为探索神经科学问题和展望新的医学应用提供了一个独特的工具包，但光学科学和工程领域对光遗传学的进展或贡献相对较少。该方案通过使用先进的光源和对光刺激的光学性质的精确控制来增强光遗传学中的神经控制。本研究项目的创新之处在于能够产生新形式的定制光，并将该光作为新形式的刺激来以新的方式激发、调制和控制光基因修饰神经元的输出。可以想象，改变和控制光刺激比从基因上改变细胞和组织的生物特性要实用得多。随着光遗传学向活体应用迈进，这一实用优势将更加显著。因此，我们的假设是，通过精确控制新的定制光刺激的光谱、时间和空间参数，有可能增强对光基因修饰神经元的电输出活动的调制和控制。为了证明我们的假设，我们的研究计划将以三个目标为指导。首先，我们将构建一个光学刺激和显微镜系统来产生这些新形式的定制光。其次，我们将对培养的海马神经元进行光刺激和电/光记录，这些神经元已经被转基因来表达通道视紫红质-2，这是一种光门控膜离子通道，以研究定制的光刺激如何改变这些细胞的电输出和活动。第三，我们将实现一个光反馈系统，测量神经元的光响应，调整光刺激参数，以优化、调制和控制电输出。这一研究项目的成功不仅将对生物光子学领域产生深远的影响，而且将对神经科学和光学科学与工程产生深远的影响。就像光遗传学有望对神经科学和医学产生广泛影响一样，这项研究可能会产生更大、更快的影响，因为可以想象，在未来，定制光刺激比修改生物学以增强光遗传控制更实用。该奖项由两个项目联合颁发-(1)生物光子学，在化学、生物工程、环境和运输系统司(工程局)，(2)生物研究仪器开发，在生物基础设施司(生物科学局)。

Proposal Number: 1403660P.I.: Boppart, Stephen A. Title: Enhanced Optogenetic Control of Neuronal Activity with Tailored Light StimuliNon-Technical ExplanationSignificance:This project will investigate how new forms of light may enhance the electrical output and control of neurons that have been genetically modified to be light-sensitive. Optogenetics is a rapidly developing field that uses molecular biology techniques to enable cellular functions to be controlled with light. When neurons (nerve cells) are genetically modified to express a light-activated membrane channel, they can be made to trigger electrical activity when exposed to light. This new level of light-activated control over neuronal activity has yet to be fully exploited, but is offering new opportunities for understanding how neurons and their electrical circuits function within the brain to form thoughts, memories, behaviors, and emotions. In optical science and engineering, advances now make it possible to generate a wide range of new forms of light with customized properties, or what is called tailored light. This research is highly significant and important for the fields of neuroscience and biophotonics. Biophotonics is the science of how light interacts with biological cells and tissues, and neuroscientists seek to understand how the brain and mind work. The new optical sources for generating tailored light in this project will change the way in which we use optogenetics to investigate and understand the function of neurons, neural circuits, and the brain. This project is also highly interdisciplinary, and will provide a unique educational and training opportunity for undergraduate and graduate students to help them solve the complex interdisciplinary problems in engineering and biology in the future. Results from this research will also be integrated into undergraduate and graduate courses in biophotonics, neuroscience, and advanced microscopy. The long-term societal benefits of this research will include raising the public's scientific literacy of how neurons and neural circuits in our brain function, and how new types of light and lasers can be used to probe the complex functions of our brain.Technical DescriptionOptogenetics is a rapidly expanding field, and one that originated out of the field of neuroscience, where genetic modifications to mammalian neurons enabled photo-activated control of membrane channels to elicit action potentials. While this concept has provided a unique toolkit for exploring neuroscience questions and envisioning new medical science applications, there have been relatively few advances or contributions to optogenetics from the fields of optical science and engineering. This proposal addresses this gap by using advanced optical sources and precise control over the optical properties of the light stimuli to enhance the neural control in optogenetics.The innovation of this research project is the ability to generate new forms of tailored light, and apply this light as new forms of stimuli to excite, modulate, and control the output of optogenetically-modified neurons in new ways. Conceivably, it is much more practical to modify and control the light stimulus than to genetically modify the biological properties of cells and tissues. As optogenetics advances to in vivo applications, this practical advantage will be even more significant. Therefore, our hypothesis is that by precisely controlling the spectral, temporal, and spatial parameters of novel tailored light stimuli, it is possible to provide enhanced modulation and control of the electrical output activity of optogenetically-modified neurons. To prove our hypothesis, our research plan will be guided by three objectives. First, we will construct an optical stimulus and microscope system to generate these new forms of tailored light. Second, we will optically stimulate and electrically/optically record from cultured hippocampal neurons that have been genetically modified to express Channelrhodopsin-2, a light-gated membrane ion channel, to investigate how tailored light stimuli alters the electrical output and activity from these cells. Third, we will implement an optical feedback system that will measure the optical response of the neurons and adjust the light stimuli parameters to optimize, modulate, and control the electrical output.The successful outcome of this research project will have far-reaching impact in not only the field of biophotonics, but also in neuroscience and optical science and engineering. Just as optogenetics is expected to make a broad impact in neuroscience, as well as medical science, this research will potentially have an even greater and more rapid impact because it will conceivably be more practical to tailor the light stimulus than to modify the biology to enhance the optogenetic control in the future.This award is being made jointly by two Programs- (1) Biophotonics, in the Division of Chemical, Bioengineering, Environmental and Transport Systems (Engineering Directorate), and (2) Instrument Development for Biological Research, in the Division of Biological Infrastructure (Biological Sciences Directorate).