睡眠・生体リズム
Sleep and Biological Rhythms
O3-8-1-1
レム睡眠中枢ニューロンとその発生学的起源に関する遺伝学的解析
Genetic analysis of the REM sleep center and its developmental origin

○林悠1, 酒井一弥2, 安田光佑1安藤れい子1, 糸原重美1
○Yu Hayashi1, Kazuya Sakai2, Kosuke Yasuda1, Julia Nguyen1, Reiko Ando1, Shigeyoshi Itohara1
理研BSI・行動遺伝学技術開発チーム1
Lab for Behavioral Genetics, RIKEN BSI, Wako1, Neuroscience Research Center, INSERM U1028, CNRS UMR5292, Lyon, France2

Sleep in mammals has evolved into a complex state composed of REM (rapid eye movement) sleep (or paradoxical sleep) and non-REM sleep (or non-paradoxical sleep). REM sleep has received a lot of attention as it is the major source of dreams. Little is known, however, about the evolutionary origin or physiologic significance of REM sleep. Furthermore, the identity of the neurons responsible for the transition between the two sleep states is controversial due to the heterogeneity and complexity of the brainstem neurons. Here, we established a genetic method that enables postnatal manipulation of neurons that derive from a specific cell lineage. This method adopts the Cre-loxP system and tetracycline inducible system to "tag" neurons that originate from a specific cell lineage, and the DREADD pharmacogenetic tool to manipulate the activity of the tagged neurons. Using this method, we genetically identified neurons in the brainstem pontine area that robustly regulate transitions between REM and non-REM sleep. Furthermore, we show that these neurons share a common developmental origin with neurons that promote arousal. Finally, we identified the vertebrate-specific molecule Netrin-G1 as a factor required for normal REM sleep. These results are expected to provide critical evidence about the neurons that regulate sleep states and provide important information about the evolutionary origin of REM and non-REM sleep.
O3-8-1-2
リン酸化による時計タンパク質の分解を介した、SIK3の概日リズム制御
A role for Salt-inducible kinase 3 (SIK3) in the circadian rhythm regulation: phosphorylation-dependent degradation of the clock protein

○早坂直人1,2, 徳田功3, 竹森洋4
○Naoto Hayasaka1,2, Isao Tokuda3, Hiroshi Takemori4
山口大院・医・機能神経解剖1, JSTさきがけ2, 立命大・理工3, 医薬基盤研 代謝シグナル4
Division of Functional Neuroanat, Dept of Neurosci, Yamaguchi Univ Grad School of Medicine1, PRESTO, Japan Science and Technology Agency (JST), Saitama, Japan2, Dept of Micro System Technology, Ritsumeikan Univ,Kyoto, Japan3, Lab of Cell Signaling and Metabolic Disease, National Inst of Biomedical Innovation, Osaka, Japan4

Protein kinases are known to play critical roles in the circadian systems. We have previously reported that MAP kinase is a functional component of the central circadian clock in mammals. In the present study, we focused on another kinase called salt-inducible kinase (SIK). SIK is a member of an AMP-activated protein kinase (AMPK) family, which has three isoforms and regulates gene expression in a variety of cells. Previous studies have demonstrated that SIK negatively regulates CREB activity by phosphorylation-dependent inactivation of the co-activator TORC (also called as CRTC), although involvement of the kinase in circadian clock machinery remains to be elucidated. We generated Sik3 knockout (KO) mice and found that they demonstrated malnourished phenotypes (lipodystrophy, hypolipidemia, and hypoglycemia) accompanied by cholestasis and cholelithiasis. The KO mice also showed abnormality in skeletal development. In addition, disruption of the Sik3 gene also resulted in significant phase delay in locomotor activity and metabolic rhythms, defect in entrainment to light/dark cycles, and significantly longer period in locomotor activity rhythms in constant darkness. These data suggest that SIK3 is involved not only in metabolism and skeletogenesis, but also in regulating circadian input, oscillator, and potentially output(s). Our data also suggest that SIK3 is involved in the regulation of the circadian clock by phosphorylation-dependent degradation of the PER clock protein through different pathway from that of casein kinase I, another key kinase in the circadian clock machinery.
O3-8-1-3
ENUを用いたフォワード・ジェネティックスにより複数の遺伝性睡眠異常マウスを同定した
Forward genetic analysis of ENU mutagenized mice identified multiple pedigrees exhibiting heritable sleep/wake abnormalities

○船戸弘正1,2,3, 佐藤牧人4, 三好千香1, 一久綾1, 一色万里子1, 後藤佑斗1, 原野加奈子1, 管野里美1, 柿崎美代1, 北川紗雪1, 冨田幸子1, 鈴木智広5, 若菜茂晴5, 柳沢正史1,2,4,6
○Hiromasa Funato1,2,3, Makito Sato4, Chika Miyoshi1, Aya Ikkyu1, Mariko Isshiki1, Yuto Goto1, Kanako Harano1, Satomi Kanno1, Miyo Kakizaki1, Sayuki Kitagawa1, Sachiko Tomita1, Tomohiro Suzuki55, Shigeharu Wakana5, Masashi Yanagisawa1,2,4,6
筑波大学 分子行動科学研究コア1, 筑波大学 国際統合睡眠医科学研究機構, 東邦大学医学部解剖学講座微細形態学分野2, 東邦大学 医学部 解剖学講座 微細形態学分野3, テキサス大学サウスウェスタン医学センター 分子遺伝学4, 理研バイオリソースセンター マウス表現型解析開発チーム5, ハワード・ヒューズ医学研究所6
Center for Behavioral Molecular Genetics, University of Tsukuba, Ibaraki, Japan1, International Institutes for Integrative Sleep Medicine, University of Tsukuba, Ibaraki, Japan and Department of Anatomy, School of Medicine, Toho University, Tokyo, Japan2, Department of Anatomy, School of Medicine, Toho University, Tokyo, Japan3, Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Texas, USA4, Technology and Development Team for Mouse Phenotype Analysis, Japan Mouse Clinic, RIKEN BioResource Center, Ibaraki, Japan5, Howard Hughes Medical Institute, USA6

Although sleep is a ubiquitous animal behavior, the molecular mechanism of sleep control remains unknown. Here we performed high-throughput screening of ENU mutagenized mice in order to identify genes regulating sleep/wake behavior. We have so far analyzed EEG/EMG data of more than 4,000 heterozygous (G1) male mice, examining 1) total time and episode duration of wake, non-REM sleep, and REM sleep, 2) theta wave appearance and muscle atonia during REM sleep, and 3) sleep parameters after automated sleep deprivation. Thirty-two mice have been identified as initial sleep phenodeviants exhibiting: long or short total wake time, short total REM sleep time, paradoxical increase of wakefulness after sleep deprivation, loss of theta activity during REM sleep, and abundant EMG activities during REM sleep. We then crossed these phenodeviants with wild-type females to examine the heritability of sleep/wake phenotype. Nine mutant pedigrees showed sleep abnormalities seen in the founder phenodeviants, which include long total wake time, short total wake time, and short total REM sleep time. Chromosomal mapping and whole exome sequencing of these sleep mutant lines are currently in progress
O3-8-1-4
概日ペースメーカー・視交叉上核神経ネットワークにおけるAVP産生ニューロンの役割
Roles of AVP-producing neurons in the central circadian pacemaker of the suprachiasmatic nucleus

○三枝理博1, 長谷川恵美1, 岡本仁2, 櫻井武1
○Michihiro Mieda1, Emi Hasegawa1, Hitoshi Okamoto2, Takeshi Sakurai1
金沢大学大学院 医学系 分子神経科学・統合生理学1, 理研BSI 発生遺伝子制御2
Dept Mol Neurosci, Kanazawa Univ, Kanazawa1, RIKEN BSI, Wako, Japan2

The suprachiasmatic nucleus (SCN) is the primary circadian pacemaker in mammals and entrains to the environmental light/dark cycle. It is composed of multiple types of neurons, and neuronal network properties are integral to normal function of the SCN. However, mechanisms underlying the SCN neuronal network have remained elusive.
As a first step to understand the principle of the SCN network, we generated mice in which Bmal1, an essential clock component, is deleted specifically in the neurons producing AVP, one of the primary neuronal types in the SCN (Avp-Bmal1-/- mice). Avp-Bmal1-/- mice showed lengthening of circadian period (by approximately 1 hour) and activity period (by approximately 5 hours, splitting-like phenotype) in constant darkness. When exposed to abrupt 8-h advance of light/dark cycle, control mice reentrained progressively to new lighting cycle over approximately 11 days. In contrast, Avp-Bmal1-/- mice did not show progressive shift of their locomotor activity during the transient cycles and reentrained faster (approximately 7 days) than control mice did. In Avp-Bmal1-/- mice, expression of Avp, Prokineticin 2, and Rgs16 was drastically reduced in the dorsomedial region of the SCN, where AVP neurons are located. Thus, circadian oscillators of SCN Avp neurons may modulate coupling of clock neurons within the SCN to determine circadian period by regulating transcription of multiple factors important for the function of these neurons in a coordinated manner.
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