title: Luteinizing hormone-releasing hormone neurons express c-fos antigen after steroid activation.
abstract: Immature female rats received implants containing 17 beta-estradiol on postnatal day 28 at 0900 h, followed 24 h later by either blank capsules or progesterone. Between 1500-1600 h on the day of progesterone (or blank capsule) implantation, these rats, a group of unoperated or sham controls, and a group of estrogen-progesterone-treated immature male rats were killed and perfused, and their brains processed for immunocytochemistry of c-fos antigen and LHRH. LHRH neurons consistently expressed c-fos after estrogen-progesterone treatment in females but not males; in only one of four females examined was c-fos induced after estrogen treatment. No fos was associated with LHRH neurons in the control groups. The LHRH neurons that expressed c-fos were located in the preoptic area and anterior hypothalamus; more rostral LHRH cells did not appear stimulated. These data demonstrate that gonadal steroids, administered in a paradigm that predictably produces timed stimulation of LH release, induce c-fos in LHRH neurons. The induction of c-fos in LHRH neurons provides a potentially useful and powerful tool for studying LHRH activation at the cellular level.
authors.affiliation: Department of Physiology, University of Pittsburgh, Pennsylvania 15217.
authors.forename: G E
authors.initials: GE
authors.lastname: Hoffman
authors.forename: W S
authors.initials: WS
authors.lastname: Lee
authors.forename: B
authors.initials: B
authors.lastname: Attardi
authors.forename: V
authors.initials: V
authors.lastname: Yann
authors.forename: M D
authors.initials: MD
authors.lastname: Fitzsimmons
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos; D014018:Tissue Distribution
chemical_list: D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol