title: Morphological effects of isoflavones (daidzein and genistein) on hypothalamic oxytocin neurons in the neonatal mouse brain slice cultures.
abstract: In adults, oxytocin (OXT) has various central functions including social behavior and reproduction. Many of these functions are steroid dependent and are also influenced by naturally occurring phytoestrogens, isoflavones (IFs). The aim of this study was, therefore, to clarify the effects of IFs on OXT neurons in the brain. In particular, the influence of IFs on the central OXT system of infant animal needs to be examined, because IFs are increasingly consumed for weaning as well as dietary supplements. We have morphologically analyzed the central OXT neurons in neonatal mice using slice cultures treated with IFs, daidzein (Ddz) and genistein (Gen). In the supraoptic nucleus (SON) of male mice, Gen decreased the size of OXT neurons, but not of female nor in the paraventricular hypothalamic nucleus (PVN) of neither gender. In female PVN, Ddz and 17β-estradiol (E(2)) increased the frequencies of varicosity on neurites in small OXT neurons (<21μm diameter of cell body). Ddz and Gen, as well as E(2), induced prominent vacuolation of the OXT neurons more frequently in male than in female mice, and in SON than in PVN. Thus, IFs can modulate the hypothalamic OXT neurons and the effects are site-specific and sexually dimorphic, suggesting that neonatal exposure to IFs may modify such a steroid-dependent development of particular neural pathways, including OXT system.
authors: Division of Applied Biology, Kyoto Institute of Technology Graduate School of Science and Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan. ryoshimu@kit.ac.jp
authors: Ryoichi
authors: R
authors: Yoshimura
authors: Erika
authors: E
authors: Yamamoto
authors: Yasuhisa
authors: Y
authors: Endo
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D007529:Isoflavones / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D009924:Organ Culture Techniques; D010121:Oxytocin / Q000378:metabolism*; D013495:Supraoptic Nucleus / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development
chemical_list: D007529:Isoflavones; D010121:Oxytocin; C004742:daidzein; D019833:Genistein