Study of a novel sexually dimorphic structure in the hypothalamus

2014 Fiscal Year Final Research Report

• Project/Area Number: 25670114
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental physiology(including physical medicine and nutritional physiology)
• Research Institution: Saitama University
• Principal Investigator: TSUKAHARA Shinji 埼玉大学, 理工学研究科, 准教授 (90318824)
• Co-Investigator(Kenkyū-buntansha): MATSUDA Kenichi 京都府立医科大学, 医学(系)研究科(研究院), 准教授 (40315932)
• Co-Investigator(Renkei-kenkyūsha): OGAWA Sonoko 筑波大学, 人間総合研究科(系), 教授 (50396610)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 視床下部 / エストロゲン受容体 / 性差 / 性分化 / エストラジオール / テストステロン

Outline of Final Research Achievements

Morphological sex differences in the brain underlie sex-biased brain functions. We recently found a hypothalamic area that has a female-biased sex difference in estrogen receptor-alpha expression (hereafter called the area X). In the current study, we examined the morphology of the area X, the effects of sex steroids on formation of the area X, and physiological roles of the area X. We found that the number of neurons in the area X of female mice was greater than that in male mice. Sex steroids affected this female-biased sex difference. Testicular testosterone in the postnatal and pubertal periods acts to decrease the number of neurons in the area X, while ovarian estradiol in the pubertal period acts to increase the number. Physiological function of the area X is still unclear, although our study showed that the area X is not related to female sexual behavior. Further studies are needed to determine the physiological functions of the area X.

Free Research Field

神経内分泌