Sexually dimorphic forebrain nucleus and social bonding

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08578
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental physiology(including physical medicine and nutritional physiology)
• Research Institution: Nippon Medical School (2019); University of Tokyo Health Sciences (2017-2018)
• Principal Investigator: Sakuma Yasuo 日本医科大学, 大学院医学研究科, 研究生 (70094307)
• Co-Investigator(Kenkyū-buntansha): 折笠 千登世 日本医科大学, 先端医学研究所, 准教授 (20270671) ; 濱田 知宏 日本医科大学, 医学部, 助教 (90312058)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: オキシトシン / 愛着 / 性指向 / 嗅覚 / フェロモン / 鋤鼻器 / 発達 / 動物介在療法

Outline of Final Research Achievements

Oxytocin (oxt) receptors in the preoptic area (POA), which include hormone-sensitive sexually dimorphic nuclus (SDN-POA), have been implicated in sexual partner preference in males in various species. In male mice with oxt knockout, preference to estrous females was lost, however, the size of the SDN-POA remained as same as in wild-type males. The observation contradicted the prevailing notion and called for a revision. In the current series of experiments, we showed (1) oxt knock-outs diminished sexual partner preference in both male and female mice; (2) a lacrimal protein in rats, cystatin-related protein 1, induces defensive response through the vomeronasal system, a major source of neural inputs to the POA; (3) ticking of the young rats, which replicated cutaneous sensory stimulation during rough-and-tumble play of the animal, established avid attachment of the animal to the experimenter: the animal would be useful in the animal assisted therapy in rehabilitation medicine.

Free Research Field

神経内分泌学・行動生理学

Academic Significance and Societal Importance of the Research Achievements

ラットでは同胞の兄弟姉妹の間で離乳から性成熟に至る幼若期に激しいじゃれ合いが起こり、これにより社会性が涵養される。ヒト験者がこのじゃれ合いをまねて幼若ラットに激しい触刺激を与えると、快感を示す超音波発声と共に、ヒト験者に更なる触刺激を要求する「手乗りラット」が馴化・育成される。触刺激を与えるヒトの側ではラットに対する愛着・親和性が成立するので、このラットは児童養護施設における自立援助や介護老人保健施設における卓上での動物介在療法に有用である。