Cellular and molecular bases for rhythmic GnRH release

有节奏 GnRH 释放的细胞和分子基础

• 批准号: 10631149
• 负责人: Suzanne M MOENTER
• 金额: $ 56.89万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10631149
• 关键词: Action Potentials; Affect; Afferent Neurons; Animal Model; Calcium; Cardiovascular system; Castration; Cell membrane; Cells; Central Nervous System; Characteristics; Closure by clamp; Communication; Couples; Data; Development; Dynorphins; Electrophysiology (science); Elements; Endocannabinoids; Excision; Failure; Feedback; Female; Fertility; Fire - disasters; Frequencies; Generations; Glutamates; Goals; Gonadal Steroid Hormones; Gonadotropin Hormone Releasing Hormone; Grant; Health; Hormonal; Hormones; Hypothalamic structure; Image; Individual; Infertility; KISS1 gene; Knowledge; Link; Mathematics; Measures; Membrane Potentials; Metabolism; Methods; Modeling; Molecular; Monitor; Mus; Neuroglia; Neurokinin B; Neurons; Neuropeptides; Neurosecretory Systems; Output; Pattern; Periodicity; Physiologic pulse; Pituitary Gland; Poisoning; Population; Potassium; Preoptic Areas; Process; Production; Property; Prostaglandins; Proteins; Reporter; Reproduction; Reproductive Health; Reproductive system; Role; Sex Differences; Steroids; Structure of nucleus infundibularis hypothalami; Synapses; Synaptic Transmission; System; Testing; Time; Transgenic Mice; Vertebrates; Whole-Cell Recordings; Work; autocrine; base; bone; extracellular; gamma-Aminobutyric Acid; genetic approach; in silico; individual variation; infertility treatment; interest; male; mathematical model; median eminence; paracrine; pharmacologic; reproductive; response; sex; stem; substance use; therapy development; voltage

Reproductive health is a window to overall health. Fifteen to 20% of couples have difficulty conceiving; failures of the reproductive system thus affect a substantial population. Beyond fertility, sex steroids alter development and function of many systems, for example, bone, the central nervous system and the cardiovascular system. Episodic release of gonadotropin-releasing hormone (GnRH) is required for fertility in vertebrates of both sexes, and shifts in frequency of these pulses are essential for female reproductive cycles. The goal of this proposal is to increase our fundamental understanding of the generation of episodic release of GnRH as a critical link to understanding and modulating fertility. The proposed work will define intrinsic properties of GnRH neurons, local network interactions, and roles of glia and postulated driver neurons located in the arcuate nucleus of the hypothalamus that coexpress kisspeptin, neurokinin B and dynorphin (KNDy neurons). Our working hypothesis is that intrinsic and network mechanisms interact in local circuits to produce the final episodic output of the GnRH neurosecretory system. We will study this system using state-of-the-art electrophysiological, imaging and chemogenetic approaches combined with local measures of GnRH release in transgenic mice in which specific neurons are identified by expression of fluorescent reporter proteins. We will also extend our studies with mathematical modeling to generate hypotheses and return these hypotheses to the lab for testing. We have two specific aims. In Aim 1, we will examine how autocrine and paracrine factors from GnRH neurons and glia alter the relationship among action potentials, intracellular calcium and GnRH release, as well as how steroid feedback in males and females modifies these relationships. We will apply this knowledge to study how GnRH neurons are coordinated to produce pulses. We hypothesize factors from these circuit elements (GnRH neurons, afferent neurons, and glia) are needed for pulse generation. We will use pharmacologic and chemogenetic approaches to study the specific roles of these elements in organizing the GnRH network. In Aim 2, we will characterize intrinsic properties and synaptic input to GnRH neurons in intact vs. castrate mice of both sexes. We will use these data to move beyond independent characterization of isolated parameters and directly study how synaptic transmission interacts with intrinsic properties of GnRH neurons to alter action potential generation. Dynamic clamp is a method that allows these interactions to be studied. This is accomplished by careful modeling of these conductances, which can then be added to and/or subtracted from cells during recording. This occurs in real time through iterative interaction with the cell’s membrane potential, so that voltage-dependent changes in conductance are precisely controlled, and effects of the conductances on the membrane potential and firing of the cell are recorded. By examining pulse generation from these two angles, an integrated picture will emerge that adds to our understanding of this phenomenon. All necessary animal models and methods are in place to complete these studies.

生殖健康是整体健康的一个窗口。 15%至20%的夫妇难以受孕；失败 因此，生殖系统的疾病影响了大量人口。除了生育能力之外，性类固醇还可以改变发育 以及许多系统的功能，例如骨骼、中枢神经系统和心血管系统。 两种脊椎动物的生育能力都需要促性腺激素释放激素（GnRH）的间歇性释放 性别和这些脉冲频率的变化对于女性生殖周期至关重要。此举的目标 提议的目的是增加我们对 GnRH 间歇性释放的基本理解 理解和调节生育能力的关键联系。拟议的工作将定义 GnRH 的内在特性 神经元、局部网络相互作用以及神经胶质细胞和位于弓状体的假定驱动神经元的作用 下丘脑核共表达 Kisspeptin、神经激肽 B 和强啡肽（KNDy 神经元）。我们的 工作假设是内在机制和网络机制在局部电路中相互作用以产生最终的 GnRH 神经分泌系统的间歇性输出。我们将使用最先进的技术来研究这个系统 电生理学、成像和化学遗传学方法与 GnRH 释放的局部测量相结合 在转基因小鼠中，通过荧光报告蛋白的表达来识别特定神经元。我们 还将通过数学建模来扩展我们的研究，以生成假设并返回这些假设 到实验室进行测试。我们有两个具体目标。在目标 1 中，我们将研究自分泌和旁分泌如何 来自 GnRH 神经元和神经胶质细胞的因子改变动作电位、细胞内钙和 GnRH 释放，以及男性和女性的类固醇反馈如何改变这些关系。我们将 应用这些知识来研究 GnRH 神经元如何协调产生脉冲。我们假设因素 脉冲生成需要这些电路元件（GnRH 神经元、传入神经元和神经胶质细胞）的作用。我们 将使用药理学和化学遗传学方法来研究这些元素在 组织 GnRH 网络。在目标 2 中，我们将描述 GnRH 的内在特性和突触输入 完整和阉割的两性小鼠的神经元。我们将利用这些数据超越独立 表征孤立参数并直接研究突触传递如何与内在相互作用 GnRH 神经元的特性改变动作电位的产生。动态钳位是一种允许这些 相互作用有待研究。这是通过对这些电导进行仔细建模来完成的，然后可以将其 在记录期间添加到细胞和/或从细胞中减去。这是通过迭代交互实时发生的 与细胞膜电位，从而精确控制电导的电压依赖性变化， 并记录电导对膜电位和细胞放电的影响。通过检查 从这两个角度产生脉冲，将会出现一幅完整的图景，这会增加我们对 这种现象。所有必要的动物模型和方法都已到位以完成这些研究。

项目成果

Gonadal Feedback Alters the Relationship between Action Potentials and Hormone Release in Gonadotropin-Releasing Hormone Neurons in Male Mice.

性腺反馈改变雄性小鼠促性腺激素释放激素神经元的动作电位与激素释放之间的关系。

• DOI: 10.1523/jneurosci.2355-22.2023
• 发表时间: 2023
• 期刊: The Journal of neuroscience : the official journal of the Society for Neuroscience
• 作者: Chen,Xi;Moenter,SuzanneM
• 通讯作者: Moenter,SuzanneM

A role for glial fibrillary acidic protein (GFAP)-expressing cells in the regulation of gonadotropin-releasing hormone (GnRH) but not arcuate kisspeptin neuron output in male mice.

• DOI: 10.7554/elife.68205
• 发表时间: 2021-07-22
• 期刊: eLife
• 影响因子: 7.7
• 作者: Vanacker C;Defazio RA;Sykes CM;Moenter SM
• 通讯作者: Moenter SM