CONTROL OF GONADOTROPIN SECRETION DURING LACTATION

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。次级项目的主要支助 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 为子项目列出的总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 这些研究的重点是与生殖功能抑制有关的负能量平衡状态。特定的代谢信号或传入神经通路的身份，传达信息的能量平衡的促性腺激素释放激素（GnRH）神经元，中央下丘脑系统调节生殖，仍然难以捉摸。该项目的一个关键假设是kisspeptin信号的抑制是GnRH抑制的主要因素。 虽然人们普遍认为低瘦素血症是连接能量平衡和GnRH抑制的关键因素，但我们最近的研究表明，将瘦素恢复到正常生理水平并不能逆转哺乳或热量限制中kisspeptin或GnRH的抑制。因此，低肽血症似乎不是导致生殖功能抑制的主要代谢因素。我们的假设是，脑干系统，如葡萄糖敏感神经元，可能是代谢信号的信息传递到kisspeptin神经元的网站。本项目重点研究两个假设：1）在负能量平衡状态下，GnRH细胞体部位以及神经纤维和终末的kisspeptin信号抑制是其抑制的主要成分; 2）脑干系统作为代谢信号的整合部位，提供负能量平衡期间kisspeptin抑制的传入信号。这些研究将确定调节控制GnRH神经元的新途径，并可能导致在负能量平衡状态下恢复生育能力的新疗法。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. These studies focus on states of negative energy balance that are associated with a suppression of reproductive function. The identity of the specific metabolic signals or afferent neural pathways that convey information about energy balance to gonadotropin-releasing hormone (GnRH) neurons, the central hypothalamic system regulating reproduction, remains elusive. A key hypothesis of this project is that suppression of kisspeptin signaling is the primary factor in the inhibition of GnRH. Although it is a widely held view that hypoleptinemia is the critical factor linking energy balance and suppressed GnRH, our recent studies demonstrate that restoring leptin to normal physiological levels does not reverse the inhibition of kisspeptin or GnRH in either lactation or caloric restriction. Thus, hypoleptinemia does not appear to be the primary metabolic factor responsible for the suppression of reproductive function. Our hypothesis is that brainstem systems, such as glucose sensing neurons, may be the site where information about metabolic signals is relayed to kisspeptin neurons. This project focuses on two hypotheses: 1) Suppression of kisspeptin signaling at the site of GnRH cell bodies and at nerve fibers and terminals are primary components in its inhibition during states of negative energy balance, and 2) Brainstem systems serve as a site of integration of metabolic signals and provide the afferent signals that are responsible for the suppression of kisspeptin during negative energy balance. These studies will identify new pathways that regulate control GnRH neurons and could lead to new treatments for restoring fertility in states of negative energy balance.