Fluorescent biosensors for imaging neurotransmitters: observing synapses in actio

用于神经递质成像的荧光生物传感器：观察活动中的突触

基本信息

批准号：
8758411
负责人：
Lin Tian
金额：
$ 234.98万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-19 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8758411
关键词：
Address Aminobutyric Acids Animals Area Autistic Disorder Behavior Behavior Control Biosensor Brain Calcium Communication Complex Computer Simulation Epilepsy Equilibrium Event Excitatory Synapse Fluorescence Future Glutamates Goals Image Imaging Device Industry Inhibitory Synapse Learning Link Logic Measures Medicine Memory Mental Depression Methods Microscope Microscopy Monitor Neurons Neurosciences Neurotransmitters Optics Outcome Population Proteins Reporting Research Resolution Sampling Schizophrenia Signal Transduction Structure Synapses Synaptic Transmission Time Tissues addiction awake base calcium indicator design drug discovery gamma-Aminobutyric Acid information processing interest nervous system disorder neural circuit neurotransmitter release novel optical sensor public health relevance relating to nervous system sensor spatiotemporal tool two-photon

项目摘要

DESCRIPTION (provided by applicant): One of the greatest challenges in neuroscience is to decipher the logic of the neural circuitry and link it to learning, memory, and behavior. Neural circuitry is a dynamic network that incorporates neuronal activity at a variety of spatial and temporal scales. Therefore, analysis of neural circuitry demands broad and dense sampling of neuronal activity across time and brain structures. Recent breakthroughs in modern microscope and protein based fluorescence sensors have brought this goal within reach. For example, application of genetically encoded calcium indicators, such as GCaMP3, combined with two-photon microscopy, has facilitated the large- scale recording of neural activity in a genetically-identified population at multiple time scales in awake, behaving animals. These applications have greatly advanced our understanding of the dynamics of neural circuitry and its control of behavior-a critical first step toward understanding complex brain function. Building upon the momentum of calcium imaging, the immediate need to accelerate future analyses of the dynamics of neural circuitry is to develop a broader suite of optical sensors to expand the kinds of neuronal activity that can be measured. One particular area of interest is synaptic transmission, a critical event of information processing in the brain that is difficult to access wth the optical tools currently available. There are two key questions that need to be addressed before we can develop a dynamic picture of synaptic transmission. First, we must understand how synaptic connectivity is linked to its activity; second, we must determine how different types of neurotransmitters balance with each other in a defined circuitry. Therefore, I plan to develop two classes of novel protein-based fluorescent sensors, using methods that have emerged only recently, to enable monitoring of synaptic transmission from these two different angles. For the first project outlined in this proposal, I will develop sensors specially designed for simultaneous recording of both synaptic activity and connectivity. Recently, I have been involved in developing a genetically-encoded neurotransmitter sensor (iGluSnfr) to directly measure released glutamate. This sensor, for the first time, offers the potential for monitoring excitatory synaptic activity in time and space. However, its ability to report synaptic connectivity, a piece f important information stored in the neural circuitry, is currently lacking. Therefore, I will develp strategies to split iGluSnfr into pre- and post-synaptic components. This designer sensor will permit simultaneous recording of both synaptic activity and connectivity, thus providing a way to find the synapses that are activity-dependent in a defined circuitry. For the second project outlined in this proposal, I will develop a new sensor to direct monitor inhibitory communication between neurons at synapses. It is known that based on the kind of neurotransmitters released, the communication between neurons can be either excitatory or inhibitory. Imbalanced excitatory and inhibitory synapses in specific neural circuitry have been implicated in an array of neurological disorders, including depression, addiction, autism, schizophrenia and epilepsy. Yet, optical sensors for directly monitoring inhibitory signals with needed spatiotemporal resolution are still missing. I will leverage computational modeling to redesign iGluSnFr to sense inhibitory neurotransmitters, such as ?-aminobutyric acid (GABA). Similarly, the splitting strategy to be developed in project one will be further utilized to split the GABA sensor into pre- and post-synaptic components. Taken together, a successful outcome of the proposed research would provide much needed imaging tools to enable neuroscientists to obtain a comprehensive view of both excitatory and inhibitory synapses in action at the cellular, tissue, and whole-animal level.

描述（由申请人提供）：神经科学中最大的挑战之一是破译神经电路的逻辑，并将其与学习，记忆和行为联系起来。神经回路是一个动态网络，在各种空间和时间尺度上结合了神经元活动。因此，对神经回路的分析需要在时间和大脑结构之间对神经元活动进行广泛而密集的采样。现代显微镜和基于蛋白质的荧光传感器的最新突破已使这一目标达到了目标。例如，遗传编码的钙指标（例如GCAMP3）与两光子显微镜相结合的应用，在清醒的多个时间尺度下，在均匀识别的遗传识别人群中，促进了神经活动的大尺度记录，行为动物。这些应用极大地提高了我们对神经回路动力学及其对行为的控制的理解 - 了解复杂的大脑功能的关键第一步。在钙成像的动量的基础上，立即需要加速对神经回路动力学的未来分析的需求是开发更广泛的光学传感器套件，以扩大可以测量的神经元活动的种类。感兴趣的一个特定领域是突触传输，这是大脑中信息处理的关键事件，难以访问当前可用的光学工具。在我们制定突触传输的动态图片之前，需要解决两个关键问题。首先，我们必须了解突触连通性如何与其活性相关。其次，我们必须确定不同类型的神经递质如何在定义的电路中彼此平衡。因此，我计划使用直到最近才出现的方法开发两类基于蛋白质的荧光传感器，以从这两个不同的角度监测突触传播。对于本提案中概述的第一个项目，我将开发专门为同时设计的传感器记录突触活动和连通性。最近，我参与了开发遗传编码的神经递质传感器（IGLUSNFR）直接测量释放谷氨酸的。该传感器首次提供了监测兴奋性的潜力时间和空间中的突触活动。但是，目前缺乏报告突触连通性的能力，即神经回路中存储的重要信息。因此，我将取消策略将iglusnfr分为突触前和突触后成分。该设计人员传感器将允许同时记录突触活动和连接性，从而提供了一种方法来找到与定义电路中活动有关的突触。对于本提案中概述的第二个项目，我将开发一个新的传感器，以指导突触下神经元之间的抑制性通信。众所周知，基于释放的神经递质类型，神经元之间的通信可能是兴奋性的或抑制性的。特定神经回路中的兴奋性和抑制性突触不平衡已与一系列神经系统疾病，包括抑郁，成瘾，自闭症，精神分裂症和癫痫。但是，仍缺少用于直接监测具有时空分辨率的抑制信号的光学传感器。我将利用计算建模来重新设计iglusnfr，以了解抑制性神经递质，例如？ - 氨基丁酸（GABA）。同样，将在项目中开发的拆分策略将进一步利用将GABA传感器分为前和突触后组件。综上所述，拟议的研究的成功结果将提供急需的成像工具，使神经科学家能够在细胞，组织和全动物级别的行动中获得兴奋性和抑制性突触的全面视图。