Feasibility of sequence memory based on theta traveling waves in the hippocampus

• Project/Area Number: 15K21193
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Life / Health / Medical informatics; Soft computing
• Research Institution: Yamaguchi University
• Principal Investigator: Samura Toshikazu 山口大学, 大学院創成科学研究科, 准教授 (30566617)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2016: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 海馬 / CA3 / 時系列記憶 / シータリズム / 進行波 / ギャップ結合 / シータ進行波 / 神経活動伝播 / リカレントネットワーク

Outline of Final Research Achievements

In this study, we examined the formation of sequence memory that are implemented on the spatiotemporal representation of a sequence by theta traveling waves in the hippocampus. Our computer simulation demonstrated that the hippocampal CA3 has a neural substrate for the input-dependent effective organization of neuronal activities in addition to the organization of unidirectionally propagating neuronal activities that correspond to theta traveling waves. These results indicate that the hippocampal CA3 has a capability to represent sequential information spatially. It is suggested that the formation of sequence memory from the spatiotemporal representation of a sequence is feasible in the hippocampus.

Research Products

• [Presentation] Efficient Control of Theta Traveling Waves by Synchronized Inhibition through Gap Junctions and GABAergic Connections in a Hippocampal CA3 Model (2017)
  • Author(s): Toshikazu Samura, Yutaka Sakai, Hatsuo Hayashi, Takeshi Aihara
  • Organizer: The 2017 International Symposium on Nonlinear Theory and Its Applications
  • Int'l Joint Research
• [Presentation] The functional roles of interaction between interneurons through gap junctions and GABAergic connections in organizing theta traveling waves in a hippocampal CA3 model (2017)
  • Author(s): Toshikazu Samura, Yutaka Sakai, Hatsuo Hayashi, Takeshi Aihara
  • Organizer: The 27th Annual Conference of Japanese Neural Network Society
• [Presentation] Synchronization of interneurons through Gap Junctions for theta traveling waves in hippocampal CA3 (2017)
  • Author(s): Toshikazu Samura, Yutaka Sakai, Hatsuo Hayashi, Takeshi Aihara
  • Organizer: The 40th Annual Meeting of the Japan Neuroscience Society
• [Presentation] Integration of spatial and non-spatial information to granule cell in hippocampus (2017)
  • Author(s): Naoki Nakajima, Hirofumi Hayakawa, Eriko Sugisaki, Toshikazu Samura, Takeshi Aihara
  • Organizer: The 40th Annual Meeting of the Japan Neuroscience Society
• [Presentation] Roles of Gap Junctions in Organizing Traveling Waves in a Hippocampal CA3 Network Model (2016)
  • Author(s): Toshikazu Samura,Yutaka Sakai, Hatsuo Hayashi, Takeshi Aihara
  • Organizer: The 23rd International Conference on Neural Information Processing
  • Place of Presentation: Kyoto University(京都府・京都市）
  • Int'l Joint Research
• [Presentation] Neural mechanisms and behavioral function of distinct two types of hippocampal sharp-wave ripples (2016)
  • Author(s): Toshikazu Samura, Akiko Saiki, Hidenori Aizawa, Takeshi Aihara, Yoshikazu Isomura, Yutaka Sakai
  • Organizer: The 39th Annual Meeting of the Japan Neuroscience Society
  • Place of Presentation: パシフィコ横浜（神奈川県・横浜市）
• [Presentation] ギャップ結合を通じた抑制性介在細胞の活動によるシータ進行波生成への影響 (2015)
  • Author(s): 佐村俊和、酒井裕、林初男、相原威
  • Organizer: 第25回日本神経回路学会全国大会
  • Place of Presentation: 電気通信大学（東京都調布市）
  • Year and Date: 2015-09-03
• [Remarks] 山口大学大学院創成科学研究科 神経回路情報処理研究室ホームページ
  • URL: http://www.ncc.csse.yamaguchi-u.ac.jp/research.html