Investigation of brainstem neurons in the regulation of gonadotropin secretion

项目摘要 拟议研究的长期目标是确定生理性神经通路。 信号调节促性腺激素分泌，而促性腺激素分泌最终决定生殖功能。调制 促黄体激素（LH）分泌决定生育能力，并控制性腺类固醇浓度， 对心血管、肌肉骨骼和心理健康产生深远影响。黄体生成素分泌脉冲 由下丘脑弓状核中的神经元组织，所述神经元含有kisspeptin、神经激肽B和 强啡肽（KNDy神经元）在男性和女性。在女性中，排卵前LH峰由雌二醇诱导 并且依赖于前腹侧脑室周围区的kisspeptin细胞（AVPVKiss 1）。但 控制这些kisspeptin细胞群的高阶神经回路仍然是一个重要的 悬而未决的问题。孤束核（NTS）位于脑干中，由一个核团组成。 接受丰富的内感受性和中枢性输入并投射广泛认为是神经元的异质群体 大脑有趣的是，这些神经元与应激期间脉冲性LH分泌的抑制有关， 促进排卵前LH峰期LH分泌增强。为了解决这个明显的 矛盾的是，这个K99/R 00的建议将测试中心假设，不同的神经元亚群， NTS通过抑制KNDy神经元抑制LH脉冲分泌，并通过 AVPVKiss 1细胞的激活。在指导阶段，我们将采用病毒介导的细胞活化标记 技术和光学透明组织的光片显微镜，以确定是否相同的神经元被激活 以及单细胞RNA测序以鉴定NTS亚群 神经元在应激和LH峰期间被激活（Aim 1）。指导阶段将包括关键的 高级神经解剖学和神经成像技术培训，下一代测序技术， 生物信息学分析，以及职业发展经验，这是必要的过渡到一个 独立的学术研究立场。在独立阶段，我建议使用化学遗传学和细胞- 特异性病毒介导的神经消融技术，以确定是否神经元的亚群中确定， 目的1是应激诱导的LH分泌抑制和KNDy细胞活化的充分和必要条件（目的 2)或排卵前LH峰和AVPVKiss 1细胞激活（目的3），并确定在脑中的位置 这些亚群的项目（目标2和3）。这些研究将启动我的独立研究计划， 提供了一个神经框架，可能会影响治疗LH改变性疾病的疗法的发展 多囊卵巢综合征的病因有哪些？总的来说， 赞助/共同赞助团队对我的科学和专业发展，加上刺激 学术环境和令人印象深刻的资源在加州大学圣地亚哥分校提供给我将确保实现 本职业发展提案的目的以及加州大学圣地亚哥分校和美国国立卫生研究院的培训使命。

PROJECT SUMMARY The long-term goal of the proposed research is to determine the neural pathways by which physiological signals regulate gonadotropin secretion, which ultimately determines reproductive function. Modulation of luteinizing hormone (LH) secretion determines fertility and controls gonadal steroid concentrations, which has profound effects on cardiovascular, musculoskeletal, and mental health. Pulses of luteinizing hormone secretion are organized by neurons in the arcuate nucleus of the hypothalamus that contain kisspeptin, neurokinin B and dynorphin (KNDy neurons) in males and females. In females, the preovulatory LH surge is induced by estradiol and is dependent upon kisspeptin cells in the anteroventral periventricular region (AVPVKiss1). However, the higher order neural circuitry that governs these populations of kisspeptin cells remains a significant outstanding question. The nucleus of the solitary tract (NTS) is located in the brainstem and consists of a heterogenous population of neurons that receive rich interoceptive and central inputs and projects widely thought the brain. Interestingly, these neurons are implicated in both the inhibition of pulsatile LH secretion during stress, and the facilitation of enhanced LH secretion during the preovulatory LH surge. To address this apparent paradox, this K99/R00 proposal will test the central hypothesis that distinct subpopulations of neurons in the NTS suppress pulsatile LH secretion via inhibition of KNDy neurons and enhance LH secretion via activation of AVPVKiss1 cells. During the mentored phase, we will employ viral-mediated cell activation labeling techniques and light sheet microscopy of optically cleared tissue to determine if the same neurons are activated during stress and the LH surge, as well as single-cell RNA sequencing to identify the subpopulations of NTS neurons that are activated during stress and the LH surge (Aim 1). The mentored phase will consist of critical training in advanced neuroanatomical and neuroimaging techniques, next generation sequencing technologies, bioinformatic analysis, as well as career development experiences that are necessary for transitioning to an independent academic research position. In the independent phase, I propose to use chemogenetic and cell- specific viral-mediated neural ablation techniques to determine whether subpopulations of neurons identified in Aim 1 are sufficient and necessary for stress-induced suppression of LH secretion and KNDy cell activation (Aim 2) or for the preovulatory LH surge and AVPVKiss1 cell activation (Aim 3) and determine the locations in the brain these subpopulations project (Aims 2 & 3). These studies will launch my independent research program and will provide a neural framework that may influence the development of therapies to treat disorders of altered LH secretion, including amenorrhea, infertility, and polycystic ovary syndrome. Collectively, the commitment of the sponsoring/co-sponsoring team to my scientific and professional development, coupled with the stimulating academic environment and impressive resources at UC San Diego available to me will ensure achievement of the aims of this Career Development proposal and the training mission of UC San Diego and the NIH.