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MIZUNO KeiGraduate School of Science, Technology and Innovation / Department of Science, Technology and InnovationProfessor
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■ Research Themes- 日本学術振興会, 科学研究費助成事業, 基盤研究(C), 熊本大学, 01 Apr. 2022 - 31 Mar. 2025子どもの生活習慣改善に導く個別化研究
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Osaka Metropolitan University, 01 Apr. 2022 - 31 Mar. 2025Identification of anti-fatigue factors for children and adolescents using fatigue transition networks
- 日本学術振興会, 科学研究費助成事業, 基盤研究(C), 京都女子大学, 01 Apr. 2020 - 31 Mar. 2023放課後等デイサービスの児童生徒に対する睡眠と疲労の客観的健康評価本研究の目的は、「学校における人間関係」に課題を抱えている児童生徒が多く利用している放課後等デイサービスの児童生徒の心身の健康状態を把握し、睡眠リズムの乱れに関連した心身の客観的バイオマーカーを明らかにし、その結果より体調不良や不登校に陥るリスクが高いと判断された児童生徒には予防に向けての支援を実施することである。 放課後等デイサービスの児童生徒を対象として、抑うつ、不安、疲労、睡眠状態などの自覚症状調査とともに、睡眠・覚醒リズム(覚醒時における活動量、居眠り回数、睡眠効率、睡眠時中途覚醒数、睡眠時間など)や、指先脈波計測による自律神経機能評価などの客観的な健康関連指標を解析し、放課後等デイサービスの児童生徒の特徴を明らかにすることを目的に研究を進めた。 2021年度もコロナ禍の中ではあったが、予定通り2020年12月に、A県の2つの放課後等デイサービスの児童生徒約40名を対象に調査を実施することができた。 放課後等デイサービスの小学生は、中・高校生と比較すると、自覚的な疲労調査や睡眠調査の結果、身体疲労、精神疲労、総合疲労、睡眠得点ともに有意に低く、男女別の分析では差がみられなかった。自律神経機能評価では、小学生と中・高校生の比較、男女別の比較では差がみられなかった。睡眠・覚醒リズム解析では、小学生と中・高校生を比較すると、睡眠時間、睡眠効率数が有意に高値であった。男女別の分析では差がみられなかった。 この結果を活用して、放課後等デイサービスの児童生徒を対象に睡眠を中心とした健康教育を、ハイリスク児童生徒には個別指導を実施し、予後調査も行うことにより支援システムの有効性を検証したい。
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Challenging Research (Exploratory), Institute of Physical and Chemical Research, 29 Jun. 2018 - 31 Mar. 2021Development of Next-Generation Health Diagnosis Method by Health Informatics Using Ultra-fine Morphological Imaging DataThis research aims to provide a technology for the early and ultra-sensitive detection of "presymptoms", a potential state of disease. We conducted imaging analysis of cultured blood cells or normal and aged animal tissues using the wide-range electron microscopy technique and virtual slide imaging, and acquired their image data. We also conducted image segmentation using deep learning and other methods to decipher and make sense of the life structures in the image. For the nuclear structure of cells, we have achieved more than 90% accuracy in recognizing their structural regions. In addition, we built a prototype of knowledge hierarchy based on image metadata by mapping to a conceptual relational model of cell morphology.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Kumamoto University, 01 Apr. 2018 - 31 Mar. 2021Study for development of treatment methods in fatigue-related pediatric disorders based on evaluations of brain function and structureThe aim of the present study was to clarify the medium- to long-term effects of treatments based on the changes of brain function and structure by using magnetic resonance imaging (MRI) and functional MRI in patients with childhood chronic fatigue syndrome and attention deficit hyperactivity disorder. Unfortunately, we could not sufficient correct data affected by COVID-19 pandemic. Although the changes in brain function and structure after the continuous treatments in these patients were not detected, autonomic nerve function and cognitive function were partly altered by the continuous treatments, suggesting these evaluation methods may be partly useful for evaluation of treatment effects.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), 01 Apr. 2017 - 31 Mar. 2020A Study on School Refusal Prevention Using Objective Health Assessment of Sleep and Fatigue for ChildrenOur study confirmed that as students progressed to higher grade levels, scores for subjective assessment of physical fatigue, mental fatigue, and other factors increased, while activity levels decreased and frequency of dozing off increased. Moreover, children who evaluated themselves as sleeping longer reported less subjective fatigue such as physical and mental fatigue, exhibited higher activity levels, and reported a lower frequency of dozing off. These results clearly indicate that sufficient sleep duration is important not only in terms of improving subjective fatigue assessment, but also in terms of improving objective fatigue indices. Physical and mental fatigue in children is related to factors such as sleep duration, daytime activity level, and autonomic nerve function. The present results clearly showed that sufficient sleep duration is crucial to decrease subjective and objective fatigue, and underscored the association between sleep duration and fatigue.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Osaka City University, 01 Apr. 2017 - 31 Mar. 2020Study for anti-fatigue effects without mask of fatigueThe aim of the present study was development of methods for preventing accumulation of fatigue and recovering from fatigue using preferred stimuli. By performing a collaborative work for cognitive task with participant’s partner after a mental fatigue-inducing task, not only subjective fatigue but also objective fatigue which corresponds to cognitive function, were trended to be improved, suggesting that this collaborative work is effective to recovery from fatigue.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (A), Institute of Physical and Chemical Research, 01 Apr. 2016 - 31 Mar. 2020Health promotion by integrated research of cohort and anti-fatigue intervention in adolescenceThe present study revealed the rate of school students with chronic fatigue and intervention factors of lifestyle behavior. In addition, we could develop the evaluation bases which can investigate the severity of fatigue, intervention effects, and treatment effects for pediatric fatigue-related disorders including childhood chronic fatigue syndrome (CCFS) by using psychophysiological methods consisted of autonomic nerve function, cognitive function and brain function.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Kumamoto University, 01 Apr. 2015 - 31 Mar. 2018Development of treatment methods based on the neural substrates associated with chronic fatigue and inattention processing in pediatricsWe investigated the effects of each treatment method in patients with childhood chronic fatigue syndrome (CCFS) and attention deficit hyperactivity disorder (ADHD) evaluated by functions of attention control and reward sensitivity. Although it was difficult to identify the treatments effects using an index of neural activity, the effects of cognitive behavioral therapy and medication treatment could be evaluated using indexes of attention control and autonomic nerve activity, suggesting that these evaluation methods are beneficial.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (A), Institute of Physical and Chemical Research, 01 Apr. 2015 - 31 Mar. 2018Brain sciences for acute and chronic fatigue and anti-fatigue using integrated neurofunctional and molecular imagingsWe investigated the associations among neuroinflammation, functions and structures of the brain and oxidative stress in order to clarify the molecular and neural mechanisms of chronic fatigue. In consistent with our previous findings of the pathology of chronic fatigue syndrome, we observed the enhancement of oxidative stress, impairment of endocrine function and neuroinflammation in a novel animal model of chronic fatigue. Atrophies of the widespread brain regions in human with chronic fatigue were observed using magnetic resonance imaging (MRI). In addition, we found that the pattern of neural activities of the brain in the resting state was significantly changed using magnetoencephalogram (MEG).
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Challenging Exploratory Research, Osaka City University, 01 Apr. 2014 - 31 Mar. 2017Order-made approaches for recovery from fatigue in childrenThe aim of the present study was the development of order-made methods for improvement of lifestyle in children by modifying a sleep-wake rhythm involved in fatigue in healthy individuals of children. In healthy individuals of elementary and junior high school, some interventions to control their lifestyle induced decrease in subjective fatigue sensation and improvement of cognitive function. However, decreases in parasympathetic nerve activity in resting state and daily activity of wake condition by these interventions, and therefore, the interpretation of results should be carefully. The contents and term of intervention should be considered in future study.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Osaka City University, 01 Apr. 2014 - 31 Mar. 2017Individual preference-based study for anti-fatigueThe aim of the present study was the development of objective evaluation methods for fatigability and recovery from fatigue based on the physiological mechanisms of fatigue of elementary and junior high school students and patients childhood chronic fatigue syndrome (CCFS). Using attention control task and autonomic nerve function test, etc., objective fatigue-evaluation methods was developed. In the CCFS patients, this method was useful for identifying not only fatigability and recovery from fatigue but also treatment effect. A preliminary epidemiological survey of fatigue revealed the trend of increase in fatigued students, suggesting that it is necessary of the progress of study to overcoming fatigue in children and adolescents.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Institute of Physical and Chemical Research, 01 Apr. 2013 - 31 Mar. 2016Anti-fatigue study based on objective evaluation methods for fatigability and recovery from fatigue in adolescenceThe aim of the present study was the development of objective evaluation methods for fatigability and recovery from fatigue based on the physiological mechanisms of fatigue of elementary and junior high school students and patients childhood chronic fatigue syndrome (CCFS). Using attention control task and autonomic nerve function test, etc., objective fatigue-evaluation methods was developed. In the CCFS patients, this method was useful for identifying not only fatigability and recovery from fatigue but also treatment effect. A preliminary epidemiological survey of fatigue revealed the trend of increase in fatigued students, suggesting that it is necessary of the progress of study to overcoming fatigue in children and adolescents.
- 日本学術振興会, 科学研究費助成事業, 新学術領域研究(研究領域提案型), 独立行政法人理化学研究所, 01 Apr. 2013 - 31 Mar. 2015学習意欲と疲労耐性による強化学習の神経基盤研究本研究では、機能的磁気共鳴画像法(functional Magnetic Resonance Imaging, fMRI)を用いて、学習行動に直結する学習意欲、および学習の持続性に寄与する疲労耐性による個体学習強化の神経基盤を解明し、その神経基盤を担う脳部位が、旧人と新人の形態学的差によって特徴づけられる部位であるか、当該領域研究との連携により検証することを目的とした。健常成人を対象に、脳内の灰白質体積量をVoxel Based Morphometry(VBM)法を用いて推定し、自己記入式質問票のChalder’s Fatigue Scaleにより算出した疲労度と灰白質体積量間の相関解析を行い、前頭前野外側部や頭頂葉の萎縮レベルと亜急性疲労レベル間の相関性を見出した。これらの脳領域は、ワーキングメモリ処理に重要な領域であり、fMRIにより2-back task(ディスプレイ上に、2個前に呈示された数字が、現在呈示されている数字と一致するか否かの判定を要するワーキングメモリ課題)作業中にもこれらの領域の活性を有することを確認した。当該領域研究班が明らかにした旧人の復元脳プロジェクト成果と本研究成果を擦り合わせると、現生人類における疲労耐性力は頭頂葉の灰白質体積に関連する可能性が見出されたことから、旧人の頭頂葉の低体積は、疲労耐性力が低かったことを示唆する。本研究とRNMHプロジェクトの融合研究は、脳形態差に基づく疲労耐性およびワーキングメモリの機能差が新人と旧人の交代劇を引き起こした新たな可能性を導いた。
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Kumamoto University, 01 Apr. 2012 - 31 Mar. 2015Development of treatment methods based on the neural substrates of fatigue - Relationship between chronic fatigue and internet addiction -The aim of this study was to clarify the neural substrates associated with motivation and reward systems and develop the methods for decrease and prevention of fatigue by controlling the autonomic nerve activity based on an objective evaluation of postexertional fatigue using the autonomic nerve function in patients with childhood chronic fatigue syndrome (CCFS) and internet addiction disorders. Decreases in the striatal activity and ability to regulate the autonomic nerve activity were observed in CCFS patients. We could develop the neurophysiological investigation methods for a treatment of dopaminergic system, regulation of autonomic nerve function and the objective evaluation for these interventions in CCFS patients.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), University of Fukui, 01 Apr. 2012 - 31 Mar. 2015A combinational analysis of brain and genetic polymorphisms in children with attention deficit/hyperactivity disorder (ADHD)Attention deficit/hyperactivity disorder (ADHD) is neurobehavioral disorder characterized by inattention, hyperactivity /impulsivity and impaired reward system function, such as delay aversion, and low reward sensitivity. We evaluated brain activation with fMRI and brain volume with VBM. We found that decreased activations of the nucleus accumbens and thalamus of the ADHD patients during only the low monetary reward condition before the treatment were improved to same level as those of the healthy adolescents after the treatment. The observed improvement in brain activity was associated with improved ADHD symptom scores. In addition, a combinational analysis of brain and genetic polymorphisms in children with ADHD revealed a significant association between the left putamen GMV reduction and COMT polymorphism. These results suggest that a combinational analysis of brain and genetic polymorphisms is useful in detecting neural basis in children with ADHD.
- 日本学術振興会, 科学研究費助成事業, 新学術領域研究(研究領域提案型), 独立行政法人理化学研究所, 01 Apr. 2011 - 31 Mar. 2013内発的報酬による社会・個体学習強化の神経基盤に関する研究学習の強化因子として学習行動に直結する学習意欲喚起に資する内発的報酬(達成感・有能感)を提案し、機能的磁気共鳴画像法(functional Magnetic Resonance Imaging, fMRI)を用いて有能感の神経基盤を明らかにしたうえで、内発的報酬により喚起される意欲が強化学習に資する神経科学的プロセスを明らかにすることを本研究の目的とした。本年度は、昨年度の行動実験成果を活用し、有能感の神経基盤を探るためのfMRI研究を実施した。課題は、学習とも関連する作業記憶(ワーキングメモリ)課題のn-back taskを用いた。n-back taskは、ディスプレイ上にn個前に呈示された数字が、現在呈示されている数字と一致するか否かの判定を要する。実際に、健常成人を対象として5つのタスク(1~5-back task)を実施した。各n-back task遂行中のfMRI計測を行いながら、同時に各n-back taskに対する有能感と意欲の程度について4段階の主観的評価を行った。有能感と意欲の設問選択時に同期した脳活動を解析した結果、有能感に伴う脳活性部位を同定できなかったが、意欲の程度と相関し線条体の活性がみられることがわかった。よって、有能感に関わる神経基盤というよりも、むしろ、有能感により喚起される意欲の神経基盤として線条体の関連性を明らかにした。さらに、線条体の活性度に依存し、外側前頭前野や頭頂葉等のn-back task関連脳部位の活性度が高かったことから、内発的報酬により喚起される意欲が、課題関連脳部位の活性度を高め学習の強化プロセスに寄与することが示唆された。
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), The Institute of Physical and Chemical Research, 2011 - 2012Molecular and neural mechanisms of altered autonomic function by fatigueSympathetic hyperactivity during rest is induced by fatigue. However, the molecular and neural mechanisms of the relationship between fatigue and change in autonomic function are unclear. The aim of the present study was to clarify the molecular and neural substrates associated with fatigue and autonomic activity in healthy volunteers using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). We found that decreases in neural activation and serotonergic function of the cingulate gyrus may be associated with the sympathetic hyperactivity in fatigue condition.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), Osaka City University, 2008 - 2010Anti-fatigue effects of intrinsic motivation using non-invasive functional neuroimagingFatigue sensation was attenuated by an intrinsic reward (IR) during a fatigue-inducing tasks. Functional magnetic resonance imaging revealed that the brain regions involved in the IR were ventral striatum (VS) and anterior cingulate cortex (ACC) during the fatigue-inducing tasks. In addition, the activations of the VS and ACC were correlated with motivation score and score for the alleviation of fatigue sensation as derived from a questionnaire, respectively. These results suggest that anti-fatigue effects of intrinsic motivation are associated with the responsiveness of the ACC.