一般口演（若手道場）
若手道場 睡眠・ストレス・神経内分泌
Wakate Dojo: Sleep / Stress / Neuroendocrine System
座長：馬場 広子（新潟医療福祉大学）・髙野 哲也（慶應義塾大学） |
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| 2022年6月30日 14:00～14:15 沖縄コンベンションセンター 会議場B3・4 第6会場
1WD06a1-01
Delineation of Neural Circuits of Galaninergic Neurons in the VLPO Implicated in Regulation of Sleep
*Kseniia Prokofeva(1,2), Yuki C. Saito(2), Arisa Hirano(2,3), Takeshi Sakurai(2,3)
1. Grad Sch Comprehens Hum Sci, Univ of Tsukuba, Tsukuba, Japan, 2. WPI-IIIS, Univ of Tsukuba, Tsukuba, Japan, 3. Fac Med, Univ of Tsukuba, Tsukuba, Japan
Keyword: sleep wake circuitry, VLPO, galanin, orexinergic system
Transition between sleep and wakefulness and maintenance of these states are precisely regulated via interactions between multiple sleep- and arousal-driving neuronal networks utilizing various chemical messengers. In this intricated circuitry, orexin neurons located in the lateral hypothalamus (LH) play a pivotal role in consolidation of wakefulness, while GABAergic and galaninergic neurons in the preoptic area, mostly concentrated in the ventrolateral preoptic nucleus (VLPO), participate in initiation and maintenance of sleep. Previous studies demonstrated that orexinergic neurons are innervated by GABAergic neurons in the VLPO and can be inhibited by the projections of the preoptic GABAergic neurons. However, connection and functional interaction between orexin neurons and galaninergic VLPO (GALVLPO) neurons has not been examined at a cellular level. Therefore, the aim of this study is to identify novel sleep-implicated neural circuits comprising of the GALVLPO and orexinergic neurons. We conducted monosynaptic retrograde rabies-mediated tracing from orexin neurons using newly generated Orexin-iCre knockin mice and visualized galanin (Gal) and vesicular GABA transporter (Vgat) mRNAs in the VLPO input neurons implementing FISH. We found that Gal-positive VLPO neurons, mainly co-expressing Vgat, make direct synaptic inputs to orexin neurons. Further, we conducted projection-specific rabies-mediated tracing from the GALVLPO→LH neurons and identified that they receive monosynaptic inputs from functionally diverse brain areas (ie, motivated behavior-, circadian rhythm- and thermoregulation-related regions). We are currently performing optogenetic stimulation of the axons of GALVLPO neurons in the LH to assess contribution of the GALVLPO→LH pathway to regulation of sleep. These findings uncover connectivity of GALVLPO neurons, while our future experiments aim to unveil the role of the circuits of GALVLPO neurons in governance of sleep. | | 2022年6月30日 14:15～14:30 沖縄コンベンションセンター 会議場B3・4 第6会場
1WD06a1-02
Vasopressin neurons in the paraventricular hypothalamus promote wakefulness via lateral hypothalamic orexin neurons
*Md Tarikul Islam(1), Florian Rumpf(2), Yusuke Tsuno(1), Shota Kodani(1), Takashi Maejima(1), Michihiro Mieda(1)
1. Kanazawa University, 2. University of Wuerzburg
Keyword: Arginine vasopressin neurons, Sleep-wake, Optogenetics, Chemogenetics
Arginine vasopressin neurons in the paraventricular hypothalamus (PVHAVP) regulate various physiology and behaviors, such as body-fluid homeostasis, stress response, social interaction, and feeding. Changes in arousal state often accompany these PVHAVP-mediated adaptive responses. However, the role of PVHAVP neurons in sleep-wake regulation has remained unknown. Here, we report the involvement of these neurons in arousal promotion. Optogenetic and chemogenetic activation of PVHAVP neurons promoted wakefulness. In contrast, chemogenetic inhibition of PVHAVP neurons reduced wakefulness. Monosynaptic rabies virus tracing revealed that PVHAVP neurons receive projections from multiple brain regions involved in sleep-wake regulation. We observed dense projections of PVHAVP neurons in the lateral hypothalamus, close to orexin (LHOrx) neurons. The optogenetic stimulation of PVHAVP neuronal fibers in the LH promoted wakefulness as well. Blocking orexin receptors attenuated the arousal effect of PVHAVP neuronal activation drastically, suggesting LHOrx neurons mediate the arousal effect of PVHAVP neurons. Moreover, PVHAVP neurons mediated the arousal induced by the melanocortin agonist, at least partially. Our data suggested that PVHAVP neurons promote wakefulness via LHOrx neurons in the physiological regulation of sleep-wake and melanocortin-induced arousal. | | 2022年6月30日 14:30～14:45 沖縄コンベンションセンター 会議場B3・4 第6会場
1WD06a1-03
隔離飼育マウスの高い攻撃性を示すマウスに対するオキシトシン・バソプレシンの作用の解析
Analysis of the effects of oxytocin and vasopressin on mice showing high aggression in isolation-rearing
*五十嵐 健人(1,2)、口岩 聡(1)、口岩 俊子(1,3)、富田 和男(1)、田中 康一(1,2)、北中 純一(2)、北中 順惠(4)、西山 信好(2)、佐藤 友昭(1)
1. 鹿児島大学大学院医歯学総合研究科、2. 兵庫医科大学大学院薬学研究科、3. 鹿児島純心大学大学院人間科学研究科、4. 兵庫医科大学大学院医学研究科
*Kento Igarashi(1,2), Satoshi Kuchiiwa(1), Toshiko Kuchiiwa(1,3), Kazuo Tomita(1), Koh-ichi Tanaka(1,2), Junichi Kitanaka(2), Nobue Kitanaka(4), Nobuyoshi Nishiyama(2), Tomoaki Sato(1)
1. Grad Sch Med Dent Sci, Kagoshima Uni, Kagoshima, Japan, 2. Grad Sch Pharm, Hyogo Col Med, Hyogo, Japan, 3. Grad Sch Human Sci, Kagoshima Immaculate Heart Univ, Kagoshima, Japan, 4. Dept Pharmacol, Hyogo Col Med, Hyogo, Japan
Keyword: SOCIAL ISOLATION STRESS, AGGRESSION, OXYTOCIN, VASOPRESSIN
[Background and purpose] The mouse Aggression Response Meter (ARM) device is an effective tool to evaluate the effects of psychotropic drugs, such as buspirone and traditional Japanese herbs by analyzing the biting behavior appeared in ddY strain mice isolation-reared from 3 weeks after birth (Kuchiiwa and Kuchiiwa, J. Neurosci. Methods, 2014; Igarashi et al., Brain Res. 2021). Resident-intruder paradigm is conventionally used to analyze aggression behavior which requires the use of encounter mice, whereas the ARM device measures the biting intensity against metal rods, reducing the burden on animals. It has also been reported that both males and females can be used (Kuchiiwa and Kuchiiwa, J. Neurosci. Methods 2016). In the present study, we analyzed the effects of oxytocin (OXT) and vasopressin (AVP) using the aggressive behavior of isolation-reared mice. [Methods and results] In the current study, we measured the biting intensity of ddY strain mice isolated and reared from 3 weeks after birth, at 11 weeks after birth. The effect of OXT or AVP administered to individuals showing high aggression was investigated. The biting intensity of male mice nasally administered with 5 μL of 0.1 mM OXT decreased by about 51% (p<0.05) and that of females also decreased by about 35% decrease (p <0.05). compared to before administration. In male mice nasally administered with 5 μL of 0.1 mM AVP, the biting intensity increased by about 27% compared to before administration (p <0.05). No change in aggression was observed in female mice receiving the same amount of AVP. Next, we performed real-time PCR using total RNA extracted from brain tissue pieces including lateral septum, and found that the expression level of OXT receptor (Oxtr) mRNA in isolated-reared female mice was about 50% lower compared with that in male mice. (p<0.05). In contrast, there was no significant difference between male and female in the expression levels of AVP1a receptor (Avpr1a) and 1b receptor (Avpr1b) mRNA. [Discussion] It was found that nasal administration of OXT reduces the aggression of both male and female mice. In addition, Oxtr mRNA expression was higher in male mice than in female mice, suggesting that OXT may act more effectively on male mice. Nasal administration of AVP resulted in increased aggressive behavior only in male mice. The above results suggest that isolated-reared mice may have male-female differences in response to OXT and AVP. | | 2022年6月30日 14:45～15:00 沖縄コンベンションセンター 会議場B3・4 第6会場
1WD06a1-04
人為的なレム睡眠増加はマウスの社会的ストレス抵抗性に影響を与えるか
Does artificially increased REM sleep affect stress resilience in mice?
*安垣 進之助(1,2)、柏木 光昭(1)、鹿糠 実香(1)、柳沢 正史(1)、林 悠(1,3)
1. 筑波大学国際統合睡眠医科学研究機構、2. 筑波大学大学院人間総合科学研究科生命システム医学専攻、3. 京都大学大学院医学研究科人間健康科学系専攻
*Shinnosuke Yasugaki(1,2), Mitsuaki Kashiwagi(1), Mika Kanuka(1), Masashi Yanagisawa(1), Yu Hayashi(1,3)
1. WPI-IIIS, Univ of Tsukuba, 2. Doc Prog in Biomed Sci, Grad Sch of Comprehensive Hum Sci, Univ of Tsukuba, 3. Dep of Hum Health Sci, Grad Sch of Med, Kyoto Univ
Keyword: depression, stress, sleep, behavior
我々の睡眠は，レム（rapid eye movement：REM）睡眠とノンレム（non-REM）睡眠にわけられる．このうちレム睡眠は，鮮明な夢を生じる睡眠段階として知られるが，その生理的役割についてはわかっていないことが多い．そこで，うつ病へ着目した．うつ病では，患者の90%以上が不眠など何らかの睡眠障害に苦しむが，興味深いことに，レム睡眠に関してはむしろ量が増加するケースが多い．しかし，現在まで，レム睡眠がストレスの軽減やうつ病の予防において有益なのか有害なのかについては，科学的に解明されていない．そこで本研究では，まず，10日間の社会的敗北ストレスがマウスの睡眠に与える影響について解析した．その結果，うつ病患者と同様に，マウスにおいてもストレス曝露後にレム睡眠が大きく増加することがわかった．さらに，レム睡眠の増加は，ストレスへの単回曝露後には顕著だった一方で，慢性曝露後にはやや鈍化する傾向がみられた．これらのデータをふまえ，次に，レム睡眠を人為的に操作し，ストレス曝露下のマウスにもたらされる作用を解析しようと試みた．当研究室では，最近，マウスの脳幹において新規のレム睡眠促進ニューロンが同定されており，このニューロンを化学遺伝学的に繰り返し興奮させることで，継続的にレム睡眠を増加させることにも成功している。この手法を用い，ストレス曝露下のマウスに対してレム睡眠を人為的に増加させ，その後のストレス誘発性行動表現型に生じる影響を検討した．驚くべきことに，このレム睡眠促進ニューロンの反復的な興奮には，社会的敗北ストレスにより生じた社会的関心の減少に対する抑制効果があることがわかった（Yasugaki et al., unpublished）．現在我々は，人為的なレム睡眠増加がどのようにしてこの行動表現型の変化に寄与しているのかを明らかにしようとしている．本研究により，うつ病の「発症」に対するレム睡眠の人為的増加による介入がもたらす作用が初めて明らかになることは，慢性的なストレス環境下におけるうつ病発症のリスクを低減させるためのヒントとなるだけでなく，うつ病の発症機序の解明や病態の理解へ向けて大きな進歩をもたらすことが期待される． | |
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