Elucidating the physiological mechanisms that control the plasticity in circadian rhythms

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06771
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44050:Animal physiological chemistry, physiology and behavioral biology-related
• Research Institution: Osaka City University
• Principal Investigator: Fuchikawa Taro 大阪市立大学, 大学院理学研究科, 准教授 (90802934)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 概日リズム / ミツバチ / 神経ペプチド / sNPF

Outline of Final Research Achievements

The present study aimed at elucidating the physiological mechanisms that control the plasticity in circadian rhythms, a phenomenon in which the presence or absence of circadian rhythms switches in response to the social environment within a social insect colony. Previous studies suggest that the control mechanism exists on the pathway from the circadian clock to motor output. In this study, we focused on short neuropeptide F (sNPF), which is thought to transmit time information in the insect brain, and attempted to analyze its dynamics and function. As a result, we found several cells in which the clock gene PERIOD and sNPF are co-expressed in the honeybee brain. This supports the hypothesis that sNPF is responsible for the transmission of time information in the honeybee brain. Further studies are needed to identify the role of sNPF in the regulation of the plasticity in circadian rhythms.

Free Research Field

時間生物学

Academic Significance and Societal Importance of the Research Achievements

昆虫における概日行動リズム出力機構は、中枢で時を刻む機構に比べ不明な点が多い。行動の制御は、活動電位といった電気的過程、神経ペプチドを含む神経伝達物質を介した化学的過程、さらに細胞内のシグナル伝達過程といった複数の要素が関わる。本研究は、上記の化学的過程の理解に焦点を当てている。昆虫脳におけるsNPFの神経解剖学的な分布はこれまでショウジョウバエ以外ではほとんど明らかになっておらず、今回、これにミツバチが加わった。ミツバチはショウジョウバエには見られない概日リズムが関与する行動を示す。本研究で見つかった時計細胞に発現する神経ペプチドは、こういった行動の制御機構に関与する可能性がある。