Analysis of neuronal remodeling during transitions between reproductive live cycle and dauer stage in C. elegans

线虫生殖生命周期和多尔阶段之间神经元重塑的分析

• 批准号: 495531075
• 负责人: Professor Dr. Thomas Dandekar
• 金额: --
• 依托单位: Zentrale Abteilung für Elektronenmikroskopie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/495531075?language=en
• 关键词: Analysis; neuronal; remodeling; during; transitions

To understand how changes in neuronal signaling affect behavior, the molecular details of neuronal communication must be combined with neuronal connectivity. An ideal model organism to study how wiring and function are connected is the nematode C. elegans. Its nervous system is much simpler compared to vertebrates or insects, but still complex enough to exhibit a range of interesting and functionally distinct motor behavior. On top of that, nematodes can undergo a unique and reversible developmental transition to the dauer stage that involves radical changes in morphology and behavior. We aim to address the question how neuronal remodeling during developmental transitions in nematodes affects function. Solving this challenge requires i) high-resolution ultrastructural imaging to identify differences in the neuronal system between dauer and adult stages, ii) a detailed functional network model of the neuronal system on the cellular and systems level, and iii) quantitative behavioral experiments to validate the predicted network output and to test different hypotheses. We acquired a full FIB-SEM (Focused Ion Beam – Scanning Electron Microscopy) dataset of the central nervous system and anterior sensory organs of C. elegans dauer in collaboration with the Schwab group at EMBL Heidelberg. We then manually traced and annotated the connectome in collaboration with the group of Dr. Mei Zhen at the University of Toronto. In further preparator work for the project, we developed automated image analysis tools to quantify the synaptic vesicle pool in electron tomograms, and trained artificial neural networks to predict cell boundaries and nuclei in FIB-SEM data. We will refine and combine these tools with algorithms to quantify cell and network morphology based on work by P. Kollmannsberger and will then apply them to newly acquired image datasets. We will then adapt and use network modeling tools developed by the Dandekar group to quantitatively predict differences in motor behavior between dauer larvae and stages of the reproductive life cycle based on these datasets. Finally, we will explore the model predictions experimentally using a behavioral video-microscopy setup. Understanding how the nematode nervous system changes during the rapid transition between normal and dauer stages might answer many unsolved questions of neuronal development and plasticity and could lead to a better understanding of biological strategies to survive adverse environmental conditions in general.

为了理解神经元信号的变化如何影响行为，神经元通信的分子细节必须与神经元连接相结合。线虫C是研究神经线路和功能如何联系的理想模式生物。优雅的与脊椎动物或昆虫相比，它的神经系统要简单得多，但仍然足够复杂，可以表现出一系列有趣且功能独特的运动行为。最重要的是，线虫可以经历一个独特的和可逆的发育过渡到dauer阶段，涉及形态和行为的根本变化。我们的目的是解决这个问题，如何在线虫发育过渡期神经重塑影响功能。解决这一挑战需要：i）高分辨率超微结构成像，以识别成年期和成年期之间神经元系统的差异; ii）细胞和系统水平上神经元系统的详细功能网络模型; iii）定量行为实验，以验证预测的网络输出并测试不同的假设。我们获得了一个完整的FIB扫描电子显微镜（聚焦离子束扫描电子显微镜）数据集的中枢神经系统和前感觉器官的C。elegans dauer与海德堡EMBL的Schwab小组合作。然后，我们与多伦多大学的Mei Zhen博士的团队合作，手动追踪并注释了连接体。在该项目的进一步研究工作中，我们开发了自动图像分析工具来量化电子断层扫描中的突触囊泡池，并训练人工神经网络来预测FIB-SEM数据中的细胞边界和细胞核。我们将改进这些工具并将其与算法联合收割机结合起来，以根据P. Kollmannsberger的工作量化细胞和网络形态，然后将其应用于新获得的图像数据集。然后，我们将适应并使用Dandekar小组开发的网络建模工具，根据这些数据集定量预测dauer幼虫和生殖生命周期阶段之间的运动行为差异。最后，我们将使用行为视频显微镜装置来实验性地探索模型预测。了解线虫神经系统在正常和dauer阶段之间的快速过渡过程中如何变化，可能会回答许多尚未解决的神经元发育和可塑性问题，并可能导致更好地理解生物学策略，以在一般不利的环境条件下生存。