Functional integration of newborn olfactory sensory neurons in the healthy and regenerating olfactory system

项目摘要/摘要 了解内源性成年出生的神经元如何在功能上整合到神经回路中可能 告知使用干细胞来源的神经元修复受损脑区的策略。嗅觉感觉神经元 (OSNs)是在所有哺乳动物的一生中产生的，为研究功能提供了一个理想的模型 在健康和再生的嗅觉系统中都有整合。我们的长期目标是确定如何 新生神经元的功能整合可以增强神经元的功能和再生能力。整体而言 这项应用的目的是确定在不成熟的发育窗口中诱发的活动是如何 影响OSN在健康和再生的嗅觉系统中的存活和整合。我们的中央 假说认为，嗅觉选择性输入对未成熟的OSN是生存和功能整合所必需的 在健康的和再生的嗅觉系统中。为了验证这一假设，我们提出了三个具体的假设 目标。首先，我们将使用活体双光子来定义未成熟OSN感官输入到OB的气味选择性 钙质成像。第二，我们将确定在未成熟的成年出生的OSN中诱发活动在其 生存和功能整合。我们将在未成熟的OSN中上调和下调诱发活动 发育阶段，并使用免疫组织化学、电子显微镜、光遗传学和体内双光子 结构和功能成像，以分析它们的存活、突触发生和功能整合。最后，我们 将确定未成熟的OSN活动在OSN输入到OB的再生中的作用。为此，我们将 化学消融OSNs，OSNs由嗅觉上皮干细胞再生，使用鼻孔操纵活动 在再生过程中的闭塞和化学发生沉默，并使用体内双光子时间推移成像跟踪 OSN传入肾小球的结构和功能再生。我们希望在这个过程中发现这种被激发的活动 不成熟对OSN的生存和整合起着关键作用。因此，我们提议的工作将有一个 通过定义内源性干细胞群体的功能整合如何衍生的重要影响 神经元受到调节，以维持和再生大脑功能。这项研究将对阐明 内源性新生神经元群体中的活动在调节其功能中的作用 整合，从而为基于干细胞的治疗的发展提供了重要的见解 修复受损神经回路的策略。我们建议的研究在概念上是创新的，提出了 在发育的未成熟阶段，感觉输入对成功的嗅觉神经元的功能整合至关重要 在健康和再生的OB，并将采用一系列技术创新的实验方法。

Project Summary/Abstract Understanding how endogenously-generated adult-born neurons functionally integrate into neural circuits may inform strategies employing stem cell-derived neurons to repair damaged brain areas. Olfactory sensory neurons (OSNs), which are generated throughout life in all mammals, provide an ideal model to study functional integration in both the healthy and the regenerating olfactory system. Our long-term goal is to determine how circuit function and regeneration can be enhanced by functional integration of newborn neurons. The overall objective of this application is to determine how evoked activity during an immature developmental window influences OSN survival and integration in the healthy and the regenerating olfactory system. Our central hypothesis is that odor selective input to immature OSNs is required for their survival and functional integration in both the healthy and the regenerating olfactory system. To test this hypothesis, we propose three specific aims. First, we will define the odor selectivity of immature OSN sensory input to the OB, using in vivo 2-photon calcium imaging. Second, we will determine the role of evoked activity in immature adult-born OSNs in their survival and functional integration. We will up- and down-regulate evoked activity in OSNs during the immature developmental stage, and use immunohistochemistry, electron microscopy, optogenetics and in vivo 2-photon structural and functional imaging to assay their survival, synaptogenesis and functional integration. Finally, we will determine the role of immature OSN activity in regeneration of OSN input to the OB. For this aim, we will chemically ablate OSNs, which regenerate from olfactory epithelium stem cells, manipulate activity using naris occlusion and chemogenetic silencing during regeneration, and use in vivo 2-photon time-lapse imaging to track structural and functional regeneration of OSN input to glomeruli. We expect to find that evoked activity during immaturity plays a key role in the survival and integration of that OSN. Hence, our proposed work will have an important impact by defining how functional integration of an endogenous population of stem cell-derived neurons is regulated to maintain and regenerate brain function. This study will be highly significant in elucidating the role of activity in an endogenously-generated population of newborn neurons in regulating their functional integration, thereby providing important insight relevant to the development of stem cell-based therapeutic strategies to repair damaged neural circuits. Our proposed research is conceptually innovative in proposing that sensory input during the immature phase of development is crucial to successful functional integration of OSNs in the healthy and regenerating OB and will employ a technically innovative array of experimental approaches.