Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
Brain Res. 2010 Dec 10;1364:103-15. doi: 10.1016/j.brainres.2010.10.026. Epub 2010 Oct 15.
Gonadotropin-releasing hormone (GnRH) secretion has two modes of release in mammalian species; the surge mode and the pulse mode. The surge mode, which is required for the induction of the preovulatory gonadotropin discharge in most species, is induced by the positive feedback of estrogen secreted by the mature ovarian follicle. The pulse mode of GnRH secretion stimulates tonic luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion which drives folliculogenesis, spermatogenesis and steroidogenesis and is negatively fine-tuned by estrogen or androgen. The GnRH pulse-generating mechanism is sensitive to environmental cues, such as photoperiod, nutrition and stress surge-generating mechanism is relatively emancipated from these environmental cues. The present article first provides a brief historical background to the work that led to the concept of the GnRH pulse generator: a hypothalamic network that is central to our understanding of the regulation of reproduction. We then discuss possible neurobiological mechanisms underlying GnRH pulse generation, and conclude by proposing that kisspeptin neurons in the arcuate nucleus are key players in this regard.
促性腺激素释放激素（GnRH）在哺乳动物中有两种分泌模式；爆发模式和脉冲模式。在大多数物种中，爆发模式是诱导排卵前促性腺激素释放所必需的，是由成熟卵巢卵泡分泌的雌激素的正反馈诱导的。 GnRH 分泌的脉冲模式刺激黄体生成素（LH）和卵泡刺激素（FSH）的持续分泌，从而驱动卵泡发生、精子发生和类固醇生成，并受到雌激素或雄激素的负调控。 GnRH 脉冲发生器机制对环境线索敏感，如光周期、营养和应激；而爆发发生器机制相对不受这些环境线索的影响。本文首先简要介绍了导致 GnRH 脉冲发生器概念的工作背景：一个对我们理解生殖调节至关重要的下丘脑网络。然后，我们讨论了 GnRH 脉冲产生的可能神经生物学机制，并最后提出弓状核中的 kisspeptin 神经元是这方面的关键参与者。
