Pan-neuronal functional imaging and anesthesia

全神经元功能成像和麻醉

基本信息

批准号：
9707361
负责人：
Christopher W Connor
金额：
$ 15.19万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-15 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9707361
关键词：
Absence of pain sensation Amnesia Anesthesia procedures Anesthesiology Anesthetics Animals Architecture Behavior Behavioral Paradigm Biological Models Brain Brain region Caenorhabditis elegans Calcium Clinical Complex Data Defect Electroencephalography Fluorescence Functional Imaging Functional Magnetic Resonance Imaging Ganglia General Anesthesia Genetic Glare Human Image Individual Knowledge Lead Longevity Maps Measurement Measures Mediating Medicine Memory Microscopy Modernization Modification Molecular Molecular Analysis Movement Mus Muscle relaxation phase Nematoda Nervous system structure Neurons Optics Pain Patients Perception Physiological Physiology Population Postoperative Period Psyche structure Research Resolution Risk Sensory Signal Transduction Somatosensory Cortex Stimulus System Techniques Technology Testing Time Transgenic Organisms Translating Translations Unconscious State calcium indicator clinical practice experience experimental study fluorescence imaging hippocampal pyramidal neuron in vivo mouse model neuronal circuitry novel optical imaging promoter receptor response theories two-photon

项目摘要

Abstract Volatile anesthetics produce all stages of general anesthesia including unconsciousness, amnesia, analgesia and muscle relaxation. Once placed into this physiological state, the experience, memory and physical response to excruciating pain are all lost. However, we still do not understand mechanistically how this state of anesthesia is produced within neuronal systems such that complex mental activity is ablated while vestigial physiology is preserved. To date, research has proceeded along essentially two tracks: either the gross measurement of neuronal activity in entire regions of the brain using fMRI and EEG (which are fundamentally limited by resolution), or analysis at the molecular level looking for specific receptors for the volatile anesthetics (which has largely foundered). Astonishingly, patients can nevertheless be promptly retrieved from this state, and empirical clinical practice has reduced the risk of anesthesia to the extent that it is now an essential and universally accepted part of the modern practice of medicine. Fortunately, using novel fluorescent microscopy, we are now able to image neuronal activity in real-time, in vivo, and at resolutions capable of simultaneously capturing the activity of individual neurons and entire populations of complex neuronal networks. In this study, we apply this technique to C. elegans in which we are able to capture the activity of the entire nervous system, and to the mouse in which we capture regions of the somatosensory cortex. To discern the effect by which clinical anesthesia is achieved, it would make sense to begin with the creature with the simplest, most tractable neuronal architecture in which anesthesia is known to be inducible. C. elegans offers a simple well-mapped nervous system (302 neurons), well characterized behavioral paradigms and amenable genetics. Moreover C. elegans is well established as a model system in anesthesiology, and displays distinct stages of gross behavior under anesthesia similar to humans. Using GCaMP, a fluorescent indicator of intracellular calcium concentration expressed transgenically under a neuronal promoter, we can capture the activity of multiple neurons optically, non-invasively, and in parallel. Our experimental system will allow us to measure activity of the individual neurons within large-scale neuronal circuits to understand how subtle modifications in discrete neuronal dynamics lead to the gross but reversible functional defects at the level of the overall nervous system that result in analgesia and physical quiescence. Our study will define the effects of volatile anesthetics over increasing neuronal complexity from individual neurons to the entire nervous system. Current technology within mammalian systems is limited in scale to small subsections of the brain. We will begin complementary imaging experiments in the somatosensory cortex of the mouse that will initiate the translation of our findings and techniques to mammalian systems.

抽象的挥发性麻醉剂产生全身麻醉的各个阶段，包括意识不清、失忆、镇痛和肌肉放松。一旦进入这种生理状态，经验、记忆和身体对剧痛的反应全部丧失。然而，我们仍然不明白这种状态是如何产生的。麻醉是在神经系统内产生的，因此复杂的心理活动被消除，而残留的生理学得以保留。迄今为止，研究基本上沿着两条轨道进行：使用功能磁共振成像 (fMRI) 和脑电图 (EEG) 测量大脑整个区域的神经元活动（这从根本上来说是受分辨率限制），或在分子水平上进行分析，寻找挥发性麻醉剂的特定受体（基本上已经失败了）。令人惊讶的是，患者仍然能够迅速从这种状态中恢复过来，经验性的临床实践已经降低了麻醉的风险，以至于它现在已成为一种必要的和必要的治疗手段。现代医学实践中被普遍接受的一部分。幸运的是，使用新型荧光显微镜，我们现在能够以能够同时在体内的分辨率对神经元活动进行实时成像捕获单个神经元和整个复杂神经元网络群的活动。在这项研究中，我们将这种技术应用于秀丽隐杆线虫，我们能够捕获整个神经系统的活动，以及我们捕获体感皮层区域的小鼠。来辨别其效果实现临床麻醉后，从最简单、最容易处理的生物开始是有意义的已知麻醉是可诱导的神经元结构。秀丽隐杆线虫提供了一个简单的、映射良好的神经系统（302 个神经元）、特征明确的行为范式和顺从的遗传学。此外C. elegans 已成为麻醉学领域的一个模型系统，并显示出不同的粗体阶段麻醉下的行为与人类相似。使用细胞内钙荧光指示剂 GCaMP 在神经元启动子下转基因表达的浓度，我们可以捕获多个神经元光学地、非侵入性地、并行地。我们的实验系统将使我们能够测量大规模神经元回路中的单个神经元，以了解离散的细微变化神经元动力学导致整个神经系统水平的严重但可逆的功能缺陷从而导致镇痛和身体静止。我们的研究将定义挥发性麻醉剂对增加从单个神经元到整个神经系统的神经元复杂性。目前的技术哺乳动物系统的规模仅限于大脑的一小部分。我们将开始互补小鼠体感皮层的成像实验将启动我们的发现的转化和哺乳动物系统的技术。