Therapeutic Effects of Oxytocin on Social Disorders in Socially-Isolated Rats

Research Project

Project/Area Number	17K16384
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Psychiatric science
Research Institution	Kochi University
Principal Investigator	TANAKA Kenjiro 高知大学, 教育研究部医療学系基礎医学部門, 助教 (30552260)
Project Period (FY)	2017-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000) Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Keywords	社会行動 / オキシトシン / 視床下部 / 発達障害 / ひきこもり / 社会的隔離 / 社会的嗜好性 / 社会不安 / 社会精神医学
Outline of Final Research Achievements	In this study, we investigated the social behaviors and the activity level of oxytocin-producing cells in rats kept in an isolated environment for about two months after weaning to clarify the effects of growing alone at an early age on their mental development. Rats are usually more interested in other individuals of the same species (social stimuli) than in simple objects (non-social stimuli). However, such properties were not observed in isolated female rats. The rats also had less access to other individuals, indicating less motivation for social engagement. We also found that, in the hypothalamic oxytocin-producing cells of the same rats, the response to contact with other individuals was reduced compared with that of normal rats.
Academic Significance and Societal Importance of the Research Achievements	本研究では成熟後の社会行動に対する生育環境の影響と、視床下部オキシトシン産生細胞の関わりが示された。これらは社会性の発達メカニズムの解明に寄与し、発達障害やそれに関連する精神疾患の病態解明に役立つ。また近年、労働人口が減少する中にあって仕事や学校に行かず長期間自宅に閉じこもる若年者、いわゆる「ひきこもり」の増加が社会問題化している。本研究で用いた動物モデルは、人間のひきこもりとは異なりその多様な病態のすべてを説明するものではないが、成長過程における社会的経験が極端に乏しいという点においては共通していることから、同モデルをひきこもりに関連する脳内分子や神経回路の特定に役立たせることも期待できる。