Elucidation of the neural network for the sucking rhythm

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K07266
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 48020:Physiology-related
• Research Institution: Showa University
• Principal Investigator: Iizuka Makito 昭和大学, 医学部, 准教授 (40274980)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: Phox2b / 吸啜 / 新生ラット / 脳幹-脊髄摘出標本 / しゃっくり

Outline of Final Research Achievements

Sucking is a rhythmic movement for infants to obtain nourishment from their mothers, but the localization of the neural network and neural mechanisms of this movement are unknown. We have generated transgenic rats expressing channelrhodopsin in Phox2b-positive neurons and found that blue light stimulation from the dorsal surface of the head can induce sucking movements. Light stimulation also elicited rhythmic activity of the phrenic nerve in the isolated brainstem-spinal cord preparations, but the rhythmic activity was synchronized with that of the trigeminal and hypoglossal nerves, indicating that this was not sucking but hiccups. Currently, we are trying to induce sucking motor rhythm by applying various drugs such as glutamate and NMDA to the brainstem-spinal cord preparations, but we have not succeeded yet.

Free Research Field

呼吸生理学

Academic Significance and Societal Importance of the Research Achievements

背側領域にあるPhox2b陽性ニューロンの特異的な刺激により誘発されるリズム活動は吸啜であると考え研究を開始したが、その後の解析によりしゃっくりであることが明らかになった。1ヶ月以上持続する難治性吃逆では患者のQOLを著しく低下させる。しゃっくりの神経機構は未だ不明な点が多く、治療は経験則に基づいて行われている。本研究によりしゃっくり中枢の位置を特定できたことは、今後の難治性しゃっくりの治療法の開発に向けて意義のある研究成果である。