RUI: Development and Maturation of Olfactory Centers in the Lobster: Influences of Serotonin and Adult Neurogenesis

RUI：龙虾嗅觉中心的发育和成熟：血清素和成体神经发生的影响

• 批准号: 0091092
• 负责人: Barbara Beltz
• 金额: $ 42.6万
• 依托单位: Wellesley College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0091092&HistoricalAwards=false
• 关键词: RUI; Development; Maturation; Olfactory; Centers

Beltz0091092The primary goals of these studies are to understand how serotonin, nitric oxide and life-long neurogenesis contribute to the development and maintenance of the olfactory pathway, using in vivo and in vitro methods. The lobster Homarus americanus is used as the experimental system because of the presence of giant serotonergic neurons that innervate the olfactory areas from early embryonic development, and because neurogenesis in the olfactory pathway persists throughout the animal's life. Prior studies have shown that serotonin influences the proliferation of newborn olfactory interneurons and promotes the branching of olfactory projection neurons. Additionally, newborn projection neurons transiently take up serotonin within the first few hours after their birth. There are 4 specific aims of our current studies: 1. The functions that are mediated by the transient serotonin uptake into newborn olfactory projection neurons will be defined using pharmacological agents that block the serotonin transporter, while testing for effects on proliferation and outgrowth of the olfactory interneurons. 2. Preliminary studies in the lobster suggest that nitric oxide (NO) also may be important in the development and maintenance of the olfactory pathway. The NO system will be defined by examining the temporal and spatial regulation of NOS in the brain using immunocytochemical methods. Further, NO levels will be altered experimentally in order to test for effects on the rate of neurogenesis among olfactory interneurons. 3. An in vitro system will be established to test hypotheses emerging from our in vivo studies. The goal of this effort is to successfully culture olfactory interneurons in order to perform three major experiments: to co-culture olfactory projection neurons with the serotonergic dorsal giant neuron, to introduce serotonin into cultures of projection neurons in order to visualize effects on branching, and to have the potential to directly manipulate the NO/cGMP pathway and observe whether cultured projection neurons are NO sensitive. 4. One test for our hypotheses regarding the importance of neurogenesis in the development and maintenance of olfactory centers, is to look at these issues in crustacean species that have determinate growth and a defined lifespan. We will therefore ask whether there is persistent proliferation in the olfactory areas of these species before, and then after, a terminal molt. These studies are relevant to developmental mechanisms in higher organisms because there are many parallels between the organization of olfactory pathways and processing even in phylogenetically distant species. In addition, these studies are exploring basic mechanisms involved in the development and maintenance of neural circuits, which may be applicable in a spectrum of other systems.

Beltz 0091092这些研究的主要目的是了解血清素，一氧化氮和终身神经发生如何有助于嗅觉通路的发展和维持，使用体内和体外方法。 龙虾Homarus americanus被用作实验系统，因为存在从早期胚胎发育开始支配嗅觉区域的巨大的嗅觉神经元，并且因为嗅觉通路中的神经发生在动物的整个生命中持续存在。先前的研究表明，5-羟色胺影响新生嗅觉中间神经元的增殖，并促进嗅觉投射神经元的分支。此外，新生的投射神经元在出生后的最初几个小时内会短暂地吸收血清素。本研究有四个具体目的：1.将使用阻断5-羟色胺转运蛋白的药理学试剂来定义由新生嗅觉投射神经元的瞬时5-羟色胺摄取介导的功能，同时测试对嗅觉中间神经元的增殖和生长的影响。 2.对龙虾的初步研究表明，一氧化氮（NO）在嗅觉通路的发展和维持中也可能很重要。 NO系统将通过使用免疫细胞化学方法检查NOS在脑中的时间和空间调节来定义。 此外，将通过实验改变NO水平，以测试对嗅觉中间神经元中神经发生速率的影响。 3.将建立一个体外系统来检验我们体内研究中出现的假设。 这项工作的目标是成功地培养嗅觉中间神经元，以执行三个主要的实验：共培养嗅觉投射神经元与多巴胺能背侧巨神经元，引入血清素到投射神经元的培养物中，以可视化对分支的影响，并有可能直接操纵NO/cGMP通路，观察培养的投射神经元是否对NO敏感。 4. 对我们关于神经发生在嗅觉中心发育和维持中的重要性的假设的一个测试是在具有确定的生长和确定的寿命的甲壳动物物种中观察这些问题。 因此，我们将询问是否有持续的增殖，在嗅觉领域的这些物种之前，然后在终端蜕皮。 这些研究与高等生物的发育机制有关，因为嗅觉通路的组织和加工之间有许多相似之处，即使在遗传学上遥远的物种中也是如此。 此外，这些研究正在探索神经回路的发展和维持所涉及的基本机制，这些机制可能适用于其他系统。