Deconstructing the cellular basis of thalamic nuclei specification by in vivo clonal analysis

 描述(申请人提供)：哺乳动物丘脑具有独特的地位，可以调节大脑皮层的各种功能，包括感觉、运动控制、学习、记忆和情绪。这些功能关键依赖于数十个丘脑核团的正常发育，每个丘脑核团都显示出与大脑皮层不同区域和不同层的传入和传出连接的特征模式。为了确定丘脑组织的基本原理，需要了解丘脑神经元是如何在早期发育过程中从神经干细胞产生并组装成特定的核的。尽管最近层状细胞结构的发育机制研究取得了进展，例如大脑皮层，但对于代表许多大脑结构的核组织的形成却知之甚少。克隆谱系分析表明，在新皮质中，由单个神经干细胞产生的神经元队列形成一个放射柱，横跨整个皮质壁，作为一个功能单位。相比之下，我们不知道丘脑的每个核是否都由来自不同神经干细胞群体的后代组成，或者是否有空间或时间组织来决定 神经干细胞后代的命运，这与单个细胞核的解剖边界不一致。拟议研究的目标是结合两名研究人员的专业知识来探索这一重要问题。长期以来，Song实验室在研究海马成体神经发生的细胞和分子机制方面一直处于领先地位，并在克隆水平上广泛使用遗传谱系追踪来确定成体干细胞的增殖和分化模式。Nakagawa实验室表征了胚胎丘脑前体细胞域的分子多样性，并为理解发育中丘脑的模式形成和神经发生机制做出了重大贡献。基于使用基于遗传的单细胞谱系追踪技术的初步数据，采用MADM(马赛克双标记分析)方法，我们假设丘脑中的单个神经干细胞产生有丝分裂后神经元，这些神经元分布在横跨几个丘脑核的放射柱中，并且由单个干细胞产生的丘脑核的谱系由初始位置决定。 始发细胞的。完成拟议的实验将是了解控制大脑中核结构发展和组织的基本机制的关键的第一步。这一认识将对未来研究早期神经发育中丘脑前体区域内失调的功能和结构后果具有重要意义。

 DESCRIPTION (provided by applicant): The mammalian thalamus is uniquely positioned to regulate diverse functions of the cerebral cortex including sensation, motor control, learning and memory and emotion. These functions critically depend on the proper development of dozens of thalamic nuclei, each of which exhibits characteristic patterns of afferent and efferent connections to and from different areas and layers of the cerebral cortex. Understanding how thalamic neurons are generated from neural stem cells and assembled to form specific nuclei during early development is needed to determine the underlying principles of thalamic organization. Despite recent advances in the study of developmental mechanisms responsible for laminar cytoarchitecture such as that of the neocortex, little is known about the formation of nuclear organization that is representative of many brain structures. Clonal lineage analysis has shown that in the neocortex, cohorts of neurons generated from individual neural stem cells form a radial column that spans the entire cortical wall and acts as a functional unit. In contrast we do not know whether thalamic nuclei are each composed of progeny derived from distinct neural stem cell populations, or if there is a spatial or temporal organization that determines the fate of neural stem cell progeny, which is not aligned with the anatomical borders of individual nuclei. The goal of the proposed research is to combine the expertise of two investigators to explore this important question. The Song laboratory has long been a leader in investigating the cellular and molecular mechanisms underlying hippocampal adult neurogenesis and has extensively used genetic lineage tracing at the clonal level to determine the patterns of proliferation and differentiation of adult stem cells. The Nakagawa laboratory characterized the molecular diversity of progenitor cell domains of the embryonic thalamus and has made significant contributions to understanding the mechanisms of patterning and neurogenesis in the developing thalamus. Based on preliminary data using a genetically-based single cell lineage tracing technique that employs the MADM (mosaic analysis of double marker) method, we hypothesize that individual neural stem cells in the thalamus produce postmitotic neurons that are distributed in radial columns that span several thalamic nuclei and that the repertoire of the thalamic nuclei that are generated from individual stem cells is determined by the initial position of the originating cell. Completion of the proposed experiments will be a critical first step towar understanding fundamental mechanisms governing the development and organization of nuclear structures in the brain. This knowledge will have important implications for future investigations of the functional and structural consequences of dysregulation within thalamic progenitor domains in early neural development.