title: Glucocorticoid receptor exhibits sexually dimorphic expression in the medaka brain.
abstract: The differential impact of stress on brain functions of males and females has been widely observed in vertebrates. Recent evidence suggests that stress-induced glucocorticoid signaling affects sexual differentiation and sex changes in teleost fish. These facts led us to postulate that there were sex differences in glucocorticoid signaling in the teleost brain that underlie some sex differences in their physiological and behavioral traits. Here we found sexually dimorphic expression of a glucocorticoid receptor gene (gr1) in the brain of medaka fish (Oryzias latipes), with females having greater expression in several preoptic and thalamic nuclei. Further, gr1 exhibits female-biased expression in neurons of the anterior parvocellular preoptic nucleus that produce the neuropeptides vasotocin and gonadotropin-releasing hormone 1 (these neuropeptides have been implicated in the regulation of neuroendocrine and behavioral functions). These findings suggest that glucocorticoids have a greater influence on physiology and behavior mediated by these neuropeptides in females than in males, which may contribute to sex differences in the brain's response to stress.
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kikuchi
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Hosono
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Yamashita
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: Yukika
authors.initials: Y
authors.lastname: Kawabata
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan. Electronic address: okubo@marine.fs.a.u-tokyo.ac.jp.
authors.forename: Kataaki
authors.initials: K
authors.lastname: Okubo
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D005260:Female; D017403:In Situ Hybridization; D008297:Male; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D009990:Oryzias / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011965:Receptors, Glucocorticoid / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012737:Sex Factors
chemical_list: D009479:Neuropeptides; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid
keywords: Brain; Glucocorticoid receptor (GR); Gonadotropin-releasing hormone (GnRH); Sex differences; Teleost; Vasotocin