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　I studied at the Sleep and Circadian Neurobiology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, from April 2018 to March 2020. At Stanford University, I mainly researched the following themes: (1) sleep basic research using mice (administering compounds with sleep or wakefulness effects to mice and examining their effects), and (2) research on circadian rhythm disorders. There are only a few institutions in the world that can conduct sleep basic research using mice, and Stanford University is a wonderful environment to immerse yourself in research, as it is home to not only psychiatrists but also neurologists and many basic researchers. In this article, I would like to review the experiments I conducted during my study abroad, using mice to verify the effects of natural compounds on wakefulness or sleep. In one study, we evaluated the effects of ginkgolides (A, B, and C) and bilobalide on arousal, locomotion, and core body temperature. The results showed that only ginkgolide B dose-dependently increased the amount of arousal and decreased the amount of NREM sleep in the physiological sleep-wake cycle of mice. In another study, we tested the sleep-inducing effects of sake yeast in mice under an acute insomnia model. We showed that sake yeast dose-dependently increased REM and non-REM sleep, decreased arousal within 6 hours after oral administration of sake yeast, and decreased locomotion and core body temperature in a new cage.Juntendo Medical Journal2022. 68(2), 115-119Special ReviewsSleep Basic Research on Verifying the Effects of Natural Compounds on Wakefulness or SleepIntroductionI studied at the Sleep and Circadian Neurobi-ology Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, USA from April 2018 to March 2020. At Stanford University, I mainly researched the following themes: (1) sleep basic research using mice (administering compounds with sleep or wakeful-ness effects to mice and examining their effects), and (2) research on circadian rhythm disorders. With the support of many people, I have been able to publish four papers as the first author1-4). In this article, I would like to review two experiments I Key words: sleep, basic research, mouse, ginkgolide, sake yeastDepartment of Psychiatry and Behavioral Science, Juntendo University Graduate School of Medicine, Tokyo, JapanCorresponding author: Shohei NishimonDepartment of Psychiatry and Behavioral Science, Juntendo University Graduate School of Medicine2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, JapanTEL&FAX: +81-3-5802-1071　E-mail: snishimo@juntendo.ac.jp353rd Triannual Meeting of the Juntendo Medical Society “Medical Research Update” 〔Held on May 22, 2021〕〔Received　Aug. 11, 2021〕〔Accepted　Dec. 6, 2021〕J-STAGE Advance published date: Feb. 16, 2022Copyright © 2022 The Juntendo Medical Society. This is an open access article distributed under the terms of Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original source is properly credited. doi: 10.14789/jmj.JMJ21-0022-Rconducted during my study abroad, in which I investigated the effects of natural compounds on wakefulness or sleep in mice. One is a validation experiment on the arousal effects of ginkgolides (A, B, and C) and bilobalide, which are terpene lactones contained in Ginkgo biloba extract. The other is an experiment to verify whether sake yeast, which has a sleep-inducing effect, can similarly induce sleep under an acute insomnia model. First, I would like to explain the surgical procedure for measuring sleep electroencephalography (EEG), electromyography (EMG), locomotion, and core body temperature of mice used in the experiment2, 4).115Shohei NISHIMON