Gonadotropin-releasing hormone (GnRH) neurons are the final common conduit from the central nervous system in the reproductive axis, controlling luteinizing hormone (LH) secretion from the gonadotropes of the anterior pituitary. Although it is generally accepted that undernutrition inhibits GnRH/LH secretion, the central mechanisms that underlie the link between energy balance and reproduction remain to be fully elucidated. Sheep have been a longstanding and invaluable animal model for examination of the nutritional regulation of GnRH/LH secretion, given their ability to serve a biomedical and agricultural purpose. In this review, we summarize work that has used the ovine model to examine the central mechanisms whereby undernutrition regulates GnRH/LH secretion. Specifically, we focus our attention to the arcuate nucleus of the hypothalamus and on neurons that express kisspeptin, neurokinin B, dynorphin, proopiomelanocortin, and neuropeptide y/agouti-related peptide (NPY/AgRP). We examine their roles in mediating the effects of leptin and insulin and their effects on LH during undernutrition, as well as their regulation under conditions of undernutrition. This review will also highlight the interactions between the aforementioned neuronal networks themselves, which may be important for our understanding of the roles each play in relaying information regarding energy status during times of undernutrition to ultimately regulate GnRH/LH secretion.

促性腺激素释放激素 (GnRH) 神经元是生殖轴中中枢神经系统的最后一个共同管道，控制垂体前叶促性腺激素的促黄体生成素 (LH) 分泌。尽管人们普遍认为营养不良会抑制 GnRH/LH 的分泌，但能量平衡与生殖之间联系的核心机制仍有待充分阐明。鉴于绵羊具有生物医学和农业用途的能力，绵羊一直是用于检查 GnRH/LH 分泌的营养调节的长期且无价的动物模型。在这篇综述中，我们总结了使用绵羊模型来检查营养不良调节 GnRH/LH 分泌的中心机制的工作。具体来说，我们将注意力集中在下丘脑的弓状核和表达亲吻肽、神经激肽 B、强啡肽、阿片黑素皮质素原和神经肽 y/刺鼠相关肽 (NPY/AgRP) 的神经元上。我们研究了它们在调节瘦素和胰岛素作用中的作用，以及它们在营养不良期间对 LH 的影响，以及它们在营养不良条件下的调节作用。本综述还将重点介绍上述神经元网络本身之间的相互作用，这对于我们理解每个神经元网络在营养不足时期传递有关能量状态的信息以最终调节 GnRH/LH 分泌方面所起的作用可能很重要。我们研究了它们在调节瘦素和胰岛素作用中的作用，以及它们在营养不良期间对 LH 的影响，以及它们在营养不良条件下的调节作用。本综述还将重点介绍上述神经元网络本身之间的相互作用，这对于我们理解每个神经元网络在营养不足时期传递有关能量状态的信息以最终调节 GnRH/LH 分泌方面所起的作用可能很重要。我们研究了它们在调节瘦素和胰岛素作用中的作用，以及它们在营养不良期间对 LH 的影响，以及它们在营养不良条件下的调节作用。本综述还将重点介绍上述神经元网络本身之间的相互作用，这对于我们理解每个神经元网络在营养不足时期传递有关能量状态的信息以最终调节 GnRH/LH 分泌方面所起的作用可能很重要。