Regulation of hippocampal mossy fiber synapses and its functional significance.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02598
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 46030:Function of nervous system-related
• Research Institution: Doshisha University
• Principal Investigator: SAKABA TAKESHI 同志社大学, 脳科学研究科, 教授 (80609511)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: シナプス / 神経機能

Outline of Final Research Achievements

In this study, we have examined the mechanisms of long-term potentiation (LTP) at rodent hippocampal mossy fiber synapses, in order to understand how the synaptic strengths are regulated in an activity-dependent manner. We have opto-genetically stimulated mossy fibers to induce LTP, and applied direct presynaptic patch clamp afterwards to elucidate presynaptic changes after LTP. Electrical properties such as action potential waveform and Ca currents were unchanged. Capacitance measurements showed that the release probability of synaptic vesicles was increased after the induction of LTP. Super-resolution microscopy has shown the accumulation of Munc13-1 and RIM1 at the active zones. Taken together, we have shown that the distribution of active zone scaffold proteins dynamically changed upon LTP, which might underlie the presynaptic plasticity at mossy fiber synapses.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

神経シナプスはms以内で神経間の伝達を高速で担う一方で、秒から時間の単位で伝達効率ダイナミックに変化し、素子レベルでの学習・記憶を担っている。本研究では、シナプス後性より理解が立ち遅れていたシナプス前性の長期シナプス増強現象の分子細胞メカニズムを、分子細胞レベルで明らかにするという基礎神経科学としての意義がある。