Structural and functional analysis of zebrafish visual circuits specified by teneurin-3

tenurin-3 指定的斑马鱼视觉回路的结构和功能分析

基本信息

批准号：
BB/M000664/1
负责人：
Robert Hindges
金额：
$ 57.92万
依托单位：
King's College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FM000664%2F1
关键词：
Structural functional analysis zebrafish visual

项目摘要

The brain is built through connections that are formed during development. These connections have to be very precise in order to allow the brain to fulfil the functions important for our behaviour. Moreover, they also have to be specific so that nerve cells for particular functions are able to communicate with each other. It is therefore not surprising that one of the major challenges in Neuroscience is to understand the mechanisms that lead to such specificity: How does one cell recognise its appropriate partner and form a connection with it? What happens when these connections are not formed correctly? In recent years, several studies, mostly done in cell culture experiments, have identified a number of molecules localised on the surface of cells that play a role in this cell recognition process. However, this list of proteins is far from complete to fully explain the diversity of connections found in the brain. Moreover, what is urgently needed is a robust system where the formation and function of such connections can be studied in the living organism. Our model described in this proposal, the visual system in zebrafish, fulfils this requirement and is excellently suited for such studies. Different neurons in the visual system are responsible to transmit various aspects of visual information to the brain, for example colour, light intensity, or the direction of a movement. Functionally related neurons connect to each other at specific places in the eye and the brain. In a previous published study, we have found that the deletion of a particular protein at the surface of neurons found in the eye and the brain leads to defects in both, cell connectivity and a specific visual function involving motion. This suggests that 1) this protein is important for the appropriate connectivity between certain neurons and 2) these cells and their connections are responsible for transmitting a specific visual information. However, there are still a lot of unknowns to fully understand this process. For example: In which neurons is the candidate protein present and what is their function? How do these cells form the connections with each other during development? Are all cells containing this protein connected to each other and transmit the same functional property or are they diverse? Do other, related proteins have a similar function? With this project we will address these questions in a clear and defined work plan. Our experiments are based on techniques that we have successfully applied before. In a first step, we will use genetic methods to label all the cells, which are positive for our gene, so that we can analyse how these cells look like and with which other cells they connect. We will then characterise the functional properties of these cells. Our previous data suggests that this visual function has to do with a specific motion of objects that are seen by the eye, but it is possible that we will uncover additional functions as well. We will analyse what happens to nerve connections when we delete the gene. Importantly, we already have generated the genetic tools needed for these experiments in our preliminary work presented in this application. Once we have uncovered the function of these cells containing our protein, we will determine if its presence is needed on both, the information-sending and information-receiving neuron. This will give important insights on the mechanism of action for these proteins. Finally, we will assess if other proteins that are related to our candidate fulfil similar functions in specifying connections and for functionally related neurons. Our work described in this project impacts on the general understanding of building connections in the brain. Such knowledge is important not only for our comprehension on brain development, but also because it can help us to develop strategies for a functional recovery after brain damage through trauma or disease.

大脑是通过开发过程中形成的连接来构建的。这些连接必须非常精确，以使大脑能够实现对我们行为重要的功能。此外，它们还必须是特定的，以便特定功能的神经细胞能够相互通信。因此，神经科学的主要挑战之一是了解导致这种特殊性的机制：一个单元格如何识别其合适的伴侣并与之建立联系是不足为奇的？当这些连接未正确形成时会发生什么？近年来，几项研究主要在细胞培养实验中进行，已经确定了许多在细胞表面上的分子，这些分子在该细胞识别过程中起作用。但是，此蛋白质清单远非完整，可以完全解释大脑中发现的连接的多样性。此外，迫切需要的是一个强大的系统，可以在活生物体中研究这种连接的形成和功能。我们在本提案中描述的模型是斑马鱼中的视觉系统，满足了这一要求，并且非常适合此类研究。视觉系统中的不同神经元负责将视觉信息的各个方面传输到大脑，例如颜色，光强度或运动的方向。功能相关的神经元在眼睛和大脑的特定位置相互连接。在先前发表的研究中，我们发现，在眼睛中发现的神经元表面的特定蛋白质的缺失，大脑会导致细胞连接性和涉及运动的特定视觉功能的缺陷。这表明1）该蛋白对于某些神经元之间的适当连通性和2）这些细胞及其连接负责传输特定的视觉信息很重要。但是，仍然有很多未知数可以充分理解这一过程。例如：候选蛋白在哪种神经元中，其功能是什么？这些细胞在开发过程中如何形成彼此之间的连接？所有包含该蛋白质的细胞彼此连接并传递相同的功能特性吗？其他相关蛋白具有相似的功能吗？通过这个项目，我们将在明确且定义的工作计划中解决这些问题。我们的实验基于我们以前成功应用的技术。第一步，我们将使用遗传方法标记所有对我们基因呈阳性的细胞，以便我们可以分析这些细胞的外观以及与哪些其他细胞连接的细胞。然后，我们将表征这些细胞的功能特性。我们以前的数据表明，此视觉功能与眼睛看到的对象的特定运动有关，但是我们也可能会发现其他功能。我们将分析删除基因时神经连接会发生什么。重要的是，我们已经在本应用程序中提出的初步工作中生成了这些实验所需的遗传工具。一旦我们发现了包含蛋白质的这些细胞的功能，我们将确定是否需要在信息范围和信息接收神经元上存在它。这将为这些蛋白质的作用机理提供重要的见解。最后，我们将评估与我们候选者相关的其他蛋白质是否在指定连接和功能相关的神经元方面执行相似的功能。我们在该项目中描述的工作影响了对大脑建筑联系的一般理解。这种知识不仅对我们对大脑发育的理解很重要，而且还因为它可以帮助我们制定通过创伤或疾病破坏脑部损伤后功能恢复的策略。