The impact of decreased GABA neurotransmission on the development of individuals on the autism spectrum.

• Project/Area Number: 20K16623
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52030:Psychiatry-related
• Research Institution: Kanazawa University
• Principal Investigator: Hirosawa Tetsu 金沢大学, 子どものこころの発達研究センター, 准教授 (80645127)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2021: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2020: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: MEG / ASD / グラフ理論 / 自閉スペクトラム症の脳内ネットワーク / てんかんの脳内ネットワーク / 自閉スペクトラムとてんかんの関係 / 脳磁図 / 脳内ネットワーク / 自閉スペクトラム症 / GABA

Outline of Research at the Start

ASD児の脳ではGABA神経伝達が低下していることが知られている。申請者は前回の研究でASD児においてはGABA神経伝達が低下しているほど、認知機能が保たれている可能性を示唆する結果を報告した。本研究ではASD児および健常児に対し脳磁計を用いて抑制性GABA 神経伝達を評価し、その低下が知能と社会性に与える長期的な影響を明らかにする。前回の研究参加者を再公募し、改めて脳磁図計測と心理評価を行う。

Outline of Final Research Achievements

We recruited mainly preschool children with ASD and typically developing children, and investigated the differences in the structure of brain neural networks using MEG. We used internationally recognized structured interviews for autism diagnosis, such as ADOS and DISCO, and K-ABC for intelligence testing, while communication disorders and obsessive-compulsive behaviors were evaluated using SRS. We estimated neural activity in 68 brain regions using MEG and visualized the brain neural networks by evaluating the similarity of neural activity between brain regions using the Phase Lag Index. We analyzed the visualized brain neural networks using graph theory and were able to find significant differences in the neural network structures between children with ASD and typically developing children.

Academic Significance and Societal Importance of the Research Achievements

この研究は、自閉症スペクトラム障害（ASD）児と健常児の脳内神経ネットワークの違いを調べ、ASDの脳の特性を明らかにすることを目的としました。未就学のASD児と健常児を対象に、MEGを用いて脳活動を計測し、脳内神経ネットワークを可視化しました。その結果、ASD児と健常児の脳内神経ネットワークには有意な違いが見られ、ASD児の脳は健常児の脳とは異なったネットワーク特性を持つ傾向があることが分かりました。この成果は、ASDの病態解明や早期診断の向上に役立つと期待されます。

Research Products

• [Journal Article] Alterations in brain networks in children with sub-threshold autism spectrum disorder: A magnetoencephalography study (2022)
  • Author(s): Shiota Yuka、Soma Daiki、Hirosawa Tetsu、Yoshimura Yuko、Tanaka Sanae、Hasegawa Chiaki、Yaoi Ken、Iwasaki Sumie、Kameya Masafumi、Yokoyama Shigeru、Kikuchi Mitsuru
  • Journal Title: Frontiers in Psychiatry Volume: 13
  • DOI: 10.3389/fpsyt.2022.959763
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Epileptiform discharges relate to altered functional brain networks in autism spectrum disorders (2021)
  • Author(s): Tetsu Hirosawa, Kyung-min An, Daiki Soma, Yuka Shiota, Masuhiko Sano, Masafumi Kameya, Shoryoku Hino, Nobushige Naito, Sanae Tanaka, Ken Yaoi, Sumie Iwasaki, Yuko Yoshimura, Mitsuru Kikuchi
  • Journal Title: Brain communications Volume: 3 Issue: 3
  • DOI: 10.1093/braincomms/fcab184
  • Peer Reviewed / Open Access
• [Journal Article] Atypical Resting State Functional Neural Network in Children With Autism Spectrum Disorder: Graph Theory Approach (2021)
  • Author(s): Daiki Soma1, Tetsu Hirosawa1,2*, Chiaki Hasegawa2, Kyung-min An2, Masafumi Kameya1, Shoryoku Hino3, Yuko Yoshimura2,4, Sou Nobukawa5, Sumie Iwasaki2, Sanae Tanaka2, Ken Yaoi2, Masuhiko Sano1, Yuka Shiota2, Nobushige Naito1 and Mitsuru Kikuchi
  • Journal Title: Frontiers in psychiatry Volume: 12
  • DOI: 10.3389/fpsyt.2021.790234
  • Peer Reviewed / Open Access