Diversification and Function of Spinal V2b-Derived Neurons

描述(由申请人提供)：这项研究将在阿根廷与Guillermo Lanuza博士合作完成，作为NIH/NINDS赠款5 R37 NS037075-09的延伸。抑制性脊髓中间神经元的功能分析(2006年8月15日-2010年3月31日)最近对脊髓发育的研究导致了一种模型，在该模型中，神经元最初由独特的遗传程序决定，该程序由在背腹受限的前体群体中表达的转录因子的组合作用控制。尽管在理解细胞命运的早期事件方面已经取得了相当大的进展，但导致成人成熟神经细胞类型的指定和产生的机制仍有待阐明。在这项研究方案中，我们将在至少两个不同的亚群中解决胚胎脊髓和脑干V2b中间神经元的多样化：a)同侧轴突延伸的抑制神经元和b)接触中央管内脑脊液(CSF)的神经元。我们将研究接触脑脊液的神经元的发育，并询问它们是否构成V2b神经元的晚出生群体。我们将通过重点研究转录因子FOXN4和Mash1在V2b前体中所起的作用来定义指定通用V2b或V2b亚型的遗传程序。此外，我们将检验我们的假设，即GATA2和GATA3控制着接触CFS的神经元的分化。最后，我们将对中央管神经元的在体功能进行测定。它们作为化学传感器和内液稳态调节器的作用将在实验中使用基因消融方法进行评估，以探索它们的功能。与公共卫生相关：这些研究将更好地理解脊髓和脑干神经元多样化的机制。更重要的是，它们将为治疗脊髓损伤、退行性疾病和呼吸功能障碍的策略奠定基础。

DESCRIPTION (provided by applicant): This research will be done in Argentina in collaboration with Dr. Guillermo Lanuza as an extension of the NIH/NINDS grant 5 R37 NS037075-09. Functional Analysis of Inhibitory Spinal Cord Interneurons (8/15/2006-3/31/2010). Recent studies in the developing spinal cord have led to a model in which neurons are initially determined by unique genetic programs controlled by the combinatorial action of transcription factors expressed in dorsoventrally restricted populations of precursors. In spite of the considerable progress made in understanding early events in cell fate specification, the mechanisms that lead to the specification and generation of mature neuronal cell types in the adult remain to be elucidated. In this research proposal we will address the diversification of embryonic V2b interneurons of the spinal cord and brainstem in at least two different subsets: a) inhibitory neurons that extend axons ipsilaterally and b) neurons that contact the cerebrospinal fluid (CSF) in the central canal. We will study the development of CSF- contacting neurons and ask whether they constitute a late-born population of V2b neurons. We will define the genetic program that specifies generic V2b or V2b subtype identity by focusing on the role that the transcription factors Foxn4 and Mash1 play in V2b precursors. In addition we will test our hypothesis that Gata2 and Gata3 control the differentiation of CFS-contacting neurons. Finally, we will determine the function in vivo of central canal neurons. Their role as chemosensors and regulators of homeostasis of the internal fluid will be assessed in experiments using genetic ablation approaches to probe their function. PUBLIC HEALTH RELEVANCE: These studies will yield a better understanding of the mechanisms that underlie neuronal diversification in the spinal cord and the brainstem. More importantly, they will lay the groundwork for strategies to treat spinal cord injury, degenerative disorders and respiratory dysfunctions.