Effects of fear stress on the development of neural network in tadpoles

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K19931
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Health science and related fields
• Research Institution: Nihon University
• Principal Investigator: MORI Tsukasa 日本大学, 生物資源科学部, 教授 (60241379)
• Co-Investigator(Kenkyū-buntansha): 早川 智 日本大学, 医学部, 教授 (30238084) ; 鍵和田 晴美 国立研究開発法人産業技術総合研究所, 生命工学領域, 主任研究員 (40443204)
• Project Period (FY): 2017-06-30 – 2021-03-31
• Keywords: 恐怖ストレス / 脳神経系 / シグナル伝達 / Xenopus / 捕食者誘導

Outline of Final Research Achievements

We found that Xenopus laevis enhanced their tail muscles and increased their swimming speeds in the presence of larval salamander predators. Herein, we investigated the induced gene expression changes in the brains of tadpoles under the threat of predation using 3′-tag digital gene expression profiling. We found that many muscle genes were expressed after 24 hours of exposure to predation. Ingenuity pathway analysis further showed that after 24 hours of a predation threat, various signal transduction genes were stimulated, such as those affecting the actin cytoskeleton and CREB pathways, and that these might increase microtubule dynamics, axonogenesis, cognition, and memory. Extension of the axons was clearly observed from the nostril to the diencephalon and was significantly increased after 24 hours of exposure to predation. The dynamic changes in the signal transductions appeared to bring about new connections in the neural networks., as suggested by the microtubule dynamics.

Free Research Field

生理生化学

Academic Significance and Societal Importance of the Research Achievements

周りの仲間が捕食されることを認識することで捕食者から恐怖ストレスを受けたカエル幼生(Xenopus lavies)は10日間の被捕食ストレスにより尾部や尾の高さを高くし、更に筋肉を増強させた。この時の脳内の遺伝子発現解析や、代謝産物解析、そして神経ネットワークの解析により恐怖ストレスが脳内ネットワークにどの様な影響を与えているのかを明らかにすることが出来た。