Molecular mechanisms of the inhibition of neglect behavior: analyses of milk components and epigenetic modifications.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K07265
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 48020:Physiology-related
• Research Institution: Takasaki University of Health and Welfare
• Principal Investigator: Shimokawa Noriaki 高崎健康福祉大学, 健康福祉学部, 教授 (90235680)
• Co-Investigator(Kenkyū-buntansha): 鯉淵 典之 群馬大学, 大学院医学系研究科, 教授 (80234681)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 育児行動 / オキシトシン / 母乳

Outline of Final Research Achievements

Changes in the concentration of oxytocin (Oxt) in breast milk of lactating mice, which appears to be necessary for the expression of nurturing behavior, were measured by ELISA. Oxt concentration was significantly higher from 8 to 12 days of lactation. We believe that this increase is necessary for the expression of nurturing behavior in offspring.
To investigate the effect of Oxt in mother's milk on the expression of nurturing behavior, low Oxt breast milk was prepared by removing about 70% of Oxt in mother's milk using Oxt antibody. We found that newborns artificially nursed in low OXT milk showed strong neglect of their offspring after parturition. Addition of Oxt to low Oxt milk significantly avoided neglect.
Taken together, Oxt in breast milk is necessary for the expression of nurturing behavior of their offspring.

Free Research Field

神経内分泌学、行動生理学

Academic Significance and Societal Importance of the Research Achievements

次世代の育児行動の発現に内分泌物質であるホルモン (Oxt) が、母乳中に外分泌されることが必要であるという研究結果を通して、内分泌物質が外分泌される生理学的理由の一つを明らかにできたことが、本研究の学術的意義である。
育児放棄（ネグレクト）は社会的に重大なインシデントであるにも関わらず、発生事例や現象の羅列、社会的な機構の不備を指摘しているだけに過ぎず、分子基盤や発生メカニズムは未だ明らかでない。本研究では、母乳中のOxtが次世代の育児行動の正常な発現に必要であることを明らかにした。Oxtシグナルの破綻によるネグレクトの発生とその回避の方途を示せたことが社会的意義である。