The role of inhibitory synaptic inputs in the acquisition of feeding

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K10048
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57010:Oral biological science-related
• Research Institution: Showa University
• Principal Investigator: Nakamura Shiro 昭和大学, 歯学部, 教授 (60384187)
• Co-Investigator(Kenkyū-buntansha): 井上 富雄 昭和大学, 歯学部, 教授 (70184760) ; 弘中 祥司 昭和大学, 歯学部, 教授 (20333619)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 抑制性シナプス伝達 / 咀嚼 / 生後発達 / 三叉神経運動ニューロン

Outline of Final Research Achievements

In this study, the characteristics of postnatal development of GABAergic and glycinergic currents evoked on the jaw-closing and jaw-opening motoneurons were analyzed to clarify the role of the inhibitory synapse formation in the acquisition of mastication in early postnatal period using patch clamp. The frequency and amplitude of glycinergic miniature inhibitory postsynaptic currents (mIPSCs) increased with postnatal development in both motoneurons; however, they were higher in masseter motoneurons than in digastric motoneurons throughout all age groups. The frequency of GABAergic mIPSCs was also higher in masseter motoneurons than in digastric motoneurons in the early postnatal period. These results indicated that the developmental characteristics of inhibitory synaptic inputs differ between motoneuron populations that perform different functions.

Free Research Field

口腔生理学

Academic Significance and Societal Importance of the Research Achievements

本研究の遂行により明らかとなった顎筋支配運動ニューロンにおけるGABA性・グリシン性シナプス伝達機構の生後発達様式は、吸啜から咀嚼への運動機能発達に重要な役割を果たしていると考えられる。今回得られた細胞生理学的データは、摂食行動の発達メカニズムの解明に大きく寄与するだけでなく、GABA性・グリシン性シナプス伝達をターゲットとした神経科学基盤型の新たな咀嚼訓練法や摂食に問題のある子どもの対処法の確立につながる波及効果が期待でき、歯科だけでなく小児医学・生涯発達学などの多くの分野に多大なインパクトを与えることができると期待される。