title: Inhibitory role of the serotonergic system on estrogen receptor α expression in the female rat hypothalamus.
abstract: The role of the serotonergic system in regulating the expression of estrogen receptor (ER) α in the hypothalamus was investigated in ovariectomized rats by injecting a serotonin synthesis inhibitor, parachlorophenylalanine (PCPA), or by destroying the dorsal raphe nucleus (DR). The number of ERα-immunoreactive (ir) cells was counted in the anteroventral periventricular nucleus in the preoptic area (AVPV), ventrolateral ventromedial hypothalamic nucleus (vlVMN), and arcuate nucleus (ARCN). Seven days after ovariectomy, 100mg/kg PCPA or saline was injected daily for 4 days. Alternatively, radiofrequency lesioning of the DR (DRL) or sham lesions were made on the same time of ovariectomy. One-day after the last injection of PCPA or 7 days after brain surgery, the brain was fixed for immunostaining of ERα and the number of ERα-ir cell were counted in the nuclei of interest. The mean number of ERα-ir cells/mm(3) (density) in the AVPV of the PCPA or DRL groups was statistically higher than that in the saline or sham group. In the vlVMN and ARCN of the PCPA or DRL groups, the mean density of ERα-ir cells was comparable to the saline or sham groups. These results suggest that the serotonergic system of the DR plays an inhibitory role on the expression of ERα in the AVPV, but not in the vlVMN and ARCN.
authors.affiliation: Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan; Laboratory of Neuroendocrinology, Department of Human Behavior and Environment Sciences, School of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.affiliation: Laboratory of Neuroendocrinology, Department of Human Behavior and Environment Sciences, School of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shimogawa
authors.affiliation: Laboratory of Neuroendocrinology, Department of Human Behavior and Environment Sciences, School of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kohagura
authors.affiliation: Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Moriizumi
authors.affiliation: Laboratory of Neuroendocrinology, Department of Human Behavior and Environment Sciences, School of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan. Electronic address: hedgehog@waseda.jp.
authors.forename: Korehito
authors.initials: K
authors.lastname: Yamanouchi
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D065847:Dorsal Raphe Nucleus / Q000502:physiology; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D010134:Fenclonine / Q000494:pharmacology*; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007032:Hypothalamus, Anterior / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010052:Ovariectomy; D011301:Preoptic Area / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017208:Rats, Wistar; D012702:Serotonin Antagonists / Q000494:pharmacology*; D014697:Ventromedial Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D012702:Serotonin Antagonists; D010134:Fenclonine
keywords: Dorsal raphe nucleus; Estrogen receptor α; Female rats; Inhibition; Parachlorophenylalanine; Serotonin