| 研究課題/領域番号 |
22K12408
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| 研究種目 |
基盤研究(C)
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| 配分区分 | 基金 |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分63040:環境影響評価関連
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| 研究機関 | 国立研究開発法人国立環境研究所 |
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研究代表者 |
Tin・Tin Win・Shwe 国立研究開発法人国立環境研究所, 環境リスク・健康領域, シニア研究員 (00391128)
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| 研究期間 (年度) |
2022-04-01 – 2025-03-31
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| 研究課題ステータス |
交付 (2022年度)
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| 配分額 *注記 |
4,160千円 (直接経費: 3,200千円、間接経費: 960千円)
2024年度: 1,300千円 (直接経費: 1,000千円、間接経費: 300千円)
2023年度: 1,170千円 (直接経費: 900千円、間接経費: 270千円)
2022年度: 1,690千円 (直接経費: 1,300千円、間接経費: 390千円)
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| キーワード | microplastics / environmental pollutants / single/combined exposure / neurobehavior / neurotoxicity / Microplastics / Environmental pollutants / Single/combined exposure / Neurotoxicity / Neurobehavior |
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| 研究開始時の研究の概要 |
Microplastics (MPs) pollution has gradually become into a global environmental problem and paid attention by government, society and academia. However, it is unclear whether exposure to MPs affects living organisms, can co-exposure with other environmental pollutants affects central nervous system and early life exposure causes developmental neurotoxicity in later life. Understanding the effects and mechanism of MPs exposure and combined exposure with well-known environmental pollutants would be helpful for neurotoxicity assessment, environmental management, and environmental conservation.
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| 研究実績の概要 |
In this first year, I aimed to investigate the effect of oral administration of polystyrene nanoplastics (PS-NPs) on brain functions and behaviors in rats. Five-week-old Sprague Dawley male rats were given 45 nm PS-NPs (Polysciences, Warrington, PA, USA) or sterile water by oral administration at doses 10 mg/kg or 50 mg/kg thrice per week for four weeks. At the age of 9-week-old, behavioral tests such as open field test (OFT), novel object recognition (NOR) test, elevated plus maze (EPM) test and nest construction (NC) test were performed. The hippocampus was collected to detect neuronal activity indicators, synaptic proteins, inflammatory cytokines, neurotrophic factors, glial markers using real-time RT-PCR and immunohistochemical analyses. Hight dose PS-NPs-exposed rats showed anxiety-like behavior and cognitive deficit. Neuronal activity indicators (cFos, early growth response 1), synaptic proteins (PSD-95, synaptophysin), neurotrophic factors (BDNF, NGF) were significantly lower whereas inflammatory cytokines (IL1-beta, TNF-alpha) and microglial marker (Iba1) were significantly higher in high dose PS-NPs-exposed rats. Our results indicate oral exposure to PS-NPs induced learning, memory impairment and anxiety-like behavior by altering neuron-glia-immune cells interaction at synaptic regions in the rat hippocampus.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
In the first year, I have performed the experiment as I planned. I have reported the results of the effects of oral exposure to polystyrene NPs on brain functions and behavior in Japan Society of Hygiene in 2023 March.
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| 今後の研究の推進方策 |
In the second year, I have a plan to perform co-exposure of PS-NP and DE-SOA. Four-week-old Sprague-Dawley (SD) male rats will be purchased from Charles River Laboratories Japan, Inc., Japan. Male rats will be allocated to four different groups (n = 8 per group) as 1) the control group, 2) nanoplatsics (NPs) oral exposure group, 3) DE-SOA inhalation exposure group and 4) NPs + DE-SOA co-exposure group. At the age of five-week, the control group will be administered by sterile water, NPs group will be administered oral polystyrene NPs 10 mg/kg or 50 mg/kg thrice per week for four weeks, DE-SOA exposure group will be given 120 microg/m3 in whole-body exposure chamber, NPs + DE-SOA exposure group will be administered polystyrene 10 mg/kg or 50 mg/kg thrice per week for four weeks and DE-SOA (118 microg/m3) in whole-body exposure chamber. Food (a commercial CE-2 diet, CLEA Japan, Inc., Tokyo, Japan) and water were given ad libitum. Exposure period will be one month. After one month exposure, at the age of six-week, behavioral tests will be performed to detect cognitive behavior, anxiety behavior, social behavioral test using Any-maze software video-assisted tracking system (Muromachi Kikai Co. Ltd., Japan). After completion of behavioral tests, the hippocampus will be collected to detect neurological and immunological biomarkers in male rats using real-time RT-PCR and immunohistochemical analyses.
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