The connectome and neurobiology of a novel model chordate, Ciona intestinalis

对神经系统功能的全面了解需要集成多种类型的数据，来自 从行为学到解剖学。最终，功能可以归结为细胞和细胞之间的连接模式 单个神经元的激活。在此应用程序中，我们提出了一组AIMS，它利用唯一的 最适合多模式神经系统研究的生物体：简单脊索动物Ciona 肠肌。针叶蝉幼虫的中枢神经系统的解剖学研究表明，它与 脊椎动物，包括前脑、中脑/后脑和脊髓的同源物。尽管有这些保守的 类似脊椎动物的特征乔纳蝌蚪仅有1毫米长，只有大约2500个细胞。此外，小蝌蚪 中枢神经系统只有177个神经元。虽然Ciona CNS的发展一直是 多年来，随着Ciona蝌蚪CNS的最近完成，新的研究机会已经开启 来自连续切片电子显微镜的药隔。这项提议的总体目标是从 连接组数据，以确定单个可识别神经元水平上的行为相关性。这个项目将 是三个在乔纳活体成像和转基因方面拥有专业知识的研究小组的联合项目， 计算机视觉和图像分析，以及电子显微镜和乔纳神经解剖学。初步数据 这里展示了乔纳蝌蚪的透明和小尺寸使它们成为生活的理想之选 使用遗传编码的钙离子或电压指示器对大脑活动进行成像。这项提议的目的将是， 首先，将Ciona扩展为神经系统功能的模型，包括对行为的详细描述， 细胞分辨率的脑图谱的生成，以及脑细胞刻板印象的量化 解剖学和连通性；第二，将这些新工具应用于神经元模式的表征 乔纳幼虫的活动利用最先进的成像和神经对感官提示做出反应 活动检测方法。连接体对神经的模式做出具体和新颖的预测 活动，而Ciona CNS的相对简单将提供一个创新的系统来验证这一点 预测。该项目在图像采集、分析和多模式集成方面提出了挑战 扩展了当前技术的限制，但具有提供无与伦比的脊索中枢神经系统视图的潜力 跨越多个层次的功能，从行为到突触。

A comprehensive understanding of nervous system function requires integration of multiple types of data, from behavioral to anatomical. Ultimately function can be reduced to the patterns of connectivity between cells and the activation of single neurons. In this application we propose a set of aims that makes use of a unique organism with optimal qualities for multimodal nervous system investigation: the simple chordate, Ciona intestinalis. The anatomy of the Ciona larval tadpole CNS shows strong conservation with the CNS of the vertebrates, including homologs of the forebrain, midbrain/hindbrain, and spinal cord. Despite these conserved vertebrate-like features the Ciona tadpole is barely 1 mm long and has only ~2500 cells. Moreover the tadpole CNS has only 177 neurons. While the development of the Ciona CNS has been the subject of investigation for many years, new research opportunities have opened with the recent completion of the Ciona tadpole CNS connectome from serial section electron microscopy. The overall goal of this proposal is to build from the connectome data to identify correlates of behavior at the level of single, identifiable neurons. This project will be the combined undertaking of three research groups with expertise in Ciona live imaging and transgenesis, computer vision and image analysis, and electron microscopy and Ciona neuroanatomy. Preliminary data presented here demonstrate that the transparency and small size of Ciona tadpoles make them ideal for live imaging of brain activity using genetically encoded Ca2+ or voltage indicators. The aims of this proposal will be, first, to expand Ciona as a model of nervous system function, including a detailed characterization of behavior, the generation of a brain atlas at cellular resolution, and the quantification of stereotypy in brain cellular anatomy and connectivity; and, second, to apply these new tools in the characterization of patterns of neuronal activity as Ciona larvae respond to sensory cues by taking advantage of state-of-the-art imaging and neural activity detection methods. The connectome makes specific and novel predictions about patterns of neural activity, and the relative simplicity of the Ciona CNS will provide an innovative system for validating such predictions. This project presents challenges in image acquisition, analysis, and multimodal integration that stretch the limits of current technology, but holds the potential to provide an unparalleled view of chordate CNS function spanning multiple levels, from behavioral to synaptic.