title: Direct and indirect regulation of gonadotropin-releasing hormone neurons by estradiol.
abstract: Estrogen signaling to GnRH neurons is critical for coordinating the preovulatory surge release of LH with follicular maturation. Until recently it was thought that estrogen signaled GnRH neurons only indirectly through numerous afferent systems. This minireview presents new evidence indicating that GnRH neurons are directly regulated by estradiol (E2), primarily through estrogen receptor (ER)-beta, and indirectly through E2-sensitive neurons in the anteroventral periventricular (AVPV) region. The data described suggest that E2 generally represses GnRH gene expression but that this repression is transiently overcome by indirect E2-dependent signals relayed by AVPV neurons. We also present evidence that the AVPV neurons responsible for relaying E2 signals to GnRH neurons are multifunctional gamma aminobutyric acid-ergic/glutamatergic/neuropeptidergic neurons.
authors.affiliation: Department of Biology, Neuroscience and Behavior Graduate Program, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003, USA. sandyp@bio.umass.edu
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Petersen
authors.forename: Erich N
authors.initials: EN
authors.lastname: Ottem
authors.forename: Clifford D
authors.initials: CD
authors.lastname: Carpenter
mesh_terms: D000818:Animals; D004958:Estradiol / Q000378:metabolism*; D047629:Estrogen Receptor beta; D005260:Female; D005786:Gene Expression Regulation; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D009474:Neurons / Q000502:physiology*; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D011960:Receptors, Estrogen / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D047629:Estrogen Receptor beta; D011960:Receptors, Estrogen; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol