Elucidating the Mechanisms of Neural Function Maintenance During Hibernation-Induced Hypothermia: An Approach Using Ca2+ Imaging

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20700
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0704:Neuroscience, brain sciences, and related fields
• Research Institution: Kansai Medical University
• Principal Investigator: YAMADA Shintaro 関西医科大学, 医学部, 研究員 (70960607)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 冬眠 / チアゾリン類恐怖臭 / ハムスター / 低体温 / in vivo Ca2+ imaging / 人工冬眠

Outline of Final Research Achievements

Hibernating animals possess an extraordinary ability to maintain neural activity even under low-temperature conditions that are intolerable for typical mammals. However, the difficulty in artificially inducing hibernation and the lack of non-invasive methods to measure neural activity during hibernation have left much about the neural cold tolerance of hibernating animals unknown. In this study, we demonstrated that the thiazoline class fear odor, which induces hypothermia in mice, can also induce hibernation-like hypothermia in hibernating hamsters. Furthermore, we applied the recently developed in vivo Ca2+ imaging technique to hamsters under hibernation-like hypothermia. The results showed that neural activity was maintained in the hibernation-like hypothermic hamsters, with a decrease in the number of calcium spikes and an increase in spike width. In contrast, non-hibernating mice exhibited abnormal calcium influx under low-temperature conditions.

Free Research Field

神経科学

Academic Significance and Societal Importance of the Research Achievements

本研究により匂い物質を利用した非侵襲的な冬眠様低体温誘導法を確立した。また、遺伝子組み換え動物がほとんど存在しない冬眠動物にアデノ随伴ウイルスを用いた遺伝子導入を行い、超小型蛍光顕微鏡を用いin vivo Ca2+ imagingを可能にした。これらの技術を利用することで、これまで難しかった冬眠における比較研究や、冬眠行動における神経機能の解明につながることが期待される。さらに、本研究でわかってきた冬眠動物の神経がもつ低体温におけるカルシウム恒常性のメカニズムが解明されることで、虚血などを始めとした神経障害や疾患の治療などにもつながる可能性が示唆された。