title: Serotonin 5-HT(1A) receptor mRNA expression in dorsal hippocampus and raphe nuclei after gonadal hormone manipulation in female rats.
abstract: Female ovarian steroids influence mood and cognition, an effect presumably mediated by the serotonergic system. A key receptor in this interplay may be the 5-HT(1A) receptor subtype. We gave adult ovariectomized female rats subcutaneous pellets containing different dosages of 17 beta-estradiol alone or in combination with progesterone, or placebo pellets, for 2 weeks. 5-HT(1A) receptor mRNA levels were analyzed by in situ hybridization in the dorsal hippocampus, dorsal and median raphe nuclei, and entorhinal cortex. Estradiol treatment alone reduced 5-HT(1A) gene expression in the dentate gyrus and the CA2 region (17 and 19% decrease, respectively). Estradiol combined with progesterone supplementation increased 5-HT(1A) gene expression versus placebo in the CA1 and CA2 subregions of the dorsal hippocampus (16 and 30% increase, respectively). Concomitantly, 5-HT(1A) mRNA expression was decreased by 13% in the ventrolateral part of the dorsal raphe nuclei, while no changes were found in the median raphe nucleus and entorhinal cortex. Chronic effects of ovarian hormones on 5-HT(1A) receptor mRNA expression appear tissue-specific and involve hippocampal subregions and the raphe nuclei. Modulation of 5-HT(1A) receptor gene expression may be of importance for gonadal steroid effects on mood and cognition.
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University Hospital, Umeå, Sweden.
authors.forename: V
authors.initials: V
authors.lastname: Birzniece
authors.forename: I M
authors.initials: IM
authors.lastname: Johansson
authors.forename: M D
authors.initials: MD
authors.lastname: Wang
authors.forename: J R
authors.initials: JR
authors.lastname: Seckl
authors.forename: T
authors.initials: T
authors.lastname: Bäckström
authors.forename: T
authors.initials: T
authors.lastname: Olsson
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006624:Hippocampus / Q000378:metabolism; D017403:In Situ Hybridization; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D011903:Raphe Nuclei / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000096:biosynthesis / Q000235:genetics*; D044263:Receptors, Serotonin, 5-HT1
chemical_list: D012333:RNA, Messenger; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D011374:Progesterone; D004958:Estradiol