Molecular Mechanisms of Respiratory Circuit Connectivity

项目摘要/摘要 呼吸是陆地生命必不可少的运动功能。发育和遗传障碍 呼吸紊乱，如婴儿猝死综合症(SIDS)和Rett综合征，通常会导致 后果。这可能是由于控制呼吸的神经回路发育受损。而当 哺乳动物呼吸的驱动力--横隔肌收缩，完全由运动控制 神经元(MN)位于膈运动柱(PMC)，呼吸受复杂的神经回路调节 在后脑里。尽管这些电路至关重要，但它们背后的分子机制 连通性在很大程度上是未知的。 我们的实验室已经证明，Hox5转录因子(TF)驱动膈神经MN连接，并调节 隔膜特异性细胞黏附分子的表达。我的初步数据显示，Hox5的表达存在差异 穿过后脑呼吸核团，可能是为了传递所需的亚型特异性特征 连通性。在这项建议中，我将研究Hox5转录因子及其下游效应器在 建立呼吸回路连接。 在目标1中，我将评估Hox5基因在呼吸前运动神经元中的表达是如何支持特定连接的。 正常回路功能所需的呼吸种群之间的关系。 在目标2中，我将使用遗传操作来确定选择的细胞黏附分子如何在下游发挥作用 Hox5 TF控制呼吸连通性和功能。 我已经开发了一种综合的方法，结合了遗传模型、RNA测序、逆行 病毒追踪和电生理学来解决这些问题。了解分子机制， 潜在呼吸系统回路的发展可能会改善那些患有肺炎的人的治疗选择 影响呼吸的发育或遗传疾病。

PROJECT SUMMARY/ABSTRACT Breathing is an essential motor function for terrestrial life. Developmental and genetic disorders that disrupt breathing, such as sudden infant death syndrome (SIDS) and Rett syndrome, often have fatal consequences. This is likely due to the impaired development of neural circuits that control breathing. While diaphragm muscle contractions, the driving force for inspiration in mammals, are controlled solely by motor neurons (MNs) located in the phrenic motor column (PMC), respiration is regulated by complex neural circuitry in the hindbrain. Despite the critical importance of these circuits, the molecular mechanisms that underlie their connectivity are largely unknown. Our lab has shown that Hox5 transcription factors (TFs) drive phrenic MN connectivity and regulate the expression of phrenic-specific cell adhesion molecules. My preliminary data indicate that Hox5 expression varies across hindbrain respiratory nuclei, perhaps acting to confer subtype-specific characteristics required for connectivity. In this proposal, I will investigate the function of Hox5 TFs and their downstream effectors in establishing respiratory circuit connectivity. In Aim 1, I will assess how Hox5 gene expression in respiratory premotor neurons underlies specific connectivity between respiratory populations required for proper circuit function. In Aim 2, I will use genetic manipulations to determine how select cell adhesion molecules act downstream of Hox5 TFs to control respiratory connectivity and function. I have developed an integrative methodology combining genetic models, RNA-sequencing, retrograde viral tracing, and electrophysiology to address these questions. Understanding the molecular mechanisms that underlie respiratory circuit development could lead to improved treatment options for those suffering from developmental or genetic diseases that affect breathing.