Understanding the neural mechanisms underlying the central circadian pacemaker by neuron type-specific genetic manipulations

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H05120
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General physiology
• Research Institution: Kanazawa University
• Principal Investigator: Mieda Michihiro 金沢大学, 医学系, 教授 (20296552)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: サーカディアンリズム / 体内時計 / 神経ネットワーク / 視床下部 / 遺伝子操作マウス

Outline of Final Research Achievements

In this study, we aimed to understand the neural mechanisms underlying the generation of robust and stable circadian rhythms by the central circadian pacemaker of the suprachiasmatic nucleus (SCN), utilizing genetically-modified mice which we have developed.
We found that vasopressin-producing neurons, one of major neuron types in the SCN, play a critical role in the generation of circadian rhythms and the determination of circadian period by the SCN neural network. In addition, we analyzed the electrophysiological characteristics of vasopressin neurons and other types of neurons in the SCN. Before this study, vasopressin neurons had been considered to be dispensable for the generation per se of circadian rhythms by the SCN network. Thus, our findings reversed the conventional views about the role of vasopressin neurons in the central circadian pacemaker.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

我々の行動や生理機能の殆どが概日リズムにより調節されるため、その変調により不眠、肥満や気分障害等、様々な健康障害・疾患リスクが増大する。現代社会では、時差や夜間勤務、生活習慣の乱れにより、概日リズムの変調は誰にでも起こりうる。本研究の成果により、SCN神経ネットワークを構成する各ニューロンの役割や、中枢体内時計の神経メカニズムが明らかになれば、概日リズム変調による様々な疾患・健康障害に対し、薬剤投与による概日リズムの調整など、より効果的に対処できる技術の開発を、大いに期待できる。