AUTHOR=Constantin Stephanie TITLE=Progress and Challenges in the Search for the Mechanisms of Pulsatile Gonadotropin-Releasing Hormone Secretion JOURNAL=Frontiers in Endocrinology VOLUME=8 YEAR=2017 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2017.00180 DOI=10.3389/fendo.2017.00180 ISSN=1664-2392 ABSTRACT=
Fertility relies on the proper functioning of the hypothalamic–pituitary–gonadal axis. The hormonal cascade begins with hypothalamic neurons secreting gonadotropin-releasing hormone (GnRH) into the hypophyseal portal system. In turn, the GnRH-activated gonadotrophs in the anterior pituitary release gonadotropins, which then act on the gonads to regulate gametogenesis and sex steroidogenesis. Finally, sex steroids close this axis by feeding back to the hypothalamus. Despite this seeming straightforwardness, the axis is orchestrated by a complex neuronal network in the central nervous system. For reproductive success, GnRH neurons, the final output of this network, must integrate and translate a wide range of cues, both environmental and physiological, to the gonadotrophs