title: Sex Differences in the Embryonic Development of the Central Oxytocin System in Mice.
abstract: Recent studies suggest that oxytocin (OXT) may be important for organising the neural circuitry that underlies adult social behaviour. Although most of the work exploring these effects has focused on early postnatal development, there is evidence that OXT may also be important during foetal development. However, without an understanding of how the OXT system develops, the ability to functionally link OXT in foetal life to adult behaviour is limited. To understand where and when OXT could be acting during embryonic development to affect the organisation of neural substrates, we examined the development of the mouse OXT system from embryonic day (E) 12.5 through postnatal day (PND) 2 using OXT receptor (OXTR) binding and a quantitative polymerase chain reaction. In both males and females, OXTR binding was observed by E16.5 in the ventricular and subventricular zones, as well as the developing amygdala. In males, OXT mRNA was not detectable until PND2, whereas it was detectable by E16.5 in females. OXTR mRNA was detected by E12.5 in both sexes, although females appear to have more OXTR mRNA during foetal development than males. The present study is significant because it is the first to reveal an unexpected sex difference in the development of the OXT system and supports the possibility that OXT during foetal development may contribute to sex differences in adult behaviour.
authors.affiliation: Laboratory of Neuroendocrinology and Behavior, Department of Biological Sciences, Kent State University, Kent, OH, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tamborski
authors.affiliation: Department of Biological Sciences, Kent State University, Kent, OH, USA.|School of Biomedical Sciences, Kent State University, Kent, OH, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Mintz
authors.affiliation: Laboratory of Neuroendocrinology and Behavior, Department of Biological Sciences, Kent State University, Kent, OH, USA.|School of Biomedical Sciences, Kent State University, Kent, OH, USA.
authors.forename: H K
authors.initials: HK
authors.lastname: Caldwell
mesh_terms: D000679:Amygdala / Q000378:metabolism*; D000818:Animals; D002552:Cerebral Ventricles / Q000378:metabolism*; D047108:Embryonic Development; D005260:Female; D008297:Male; D051379:Mice; D011247:Pregnancy; D011869:Radioligand Assay; D018045:Receptors, Oxytocin / Q000378:metabolism*; D012727:Sex Characteristics; D013997:Time Factors
chemical_list: D018045:Receptors, Oxytocin
keywords: amygdala; foetal development; quantitative PCR; receptor binding