e ポスター（学部生）

e ポスター（学部生） e Poster (undergraduate)

2020/9/10　14:00～15:00　オンデマンドB-2 PU1 早産による生後のニューロン新生の低下 Decreased postnatal neurogenesis in a mouse model of preterm birth 五軒矢桜¹、川瀬恒哉^1,2、伊藤晃¹、澤田雅人^1,3、岩田欧介²、齋藤伸治²、澤本和延^1,3 1. 名古屋市立大学大学院医学研究科脳神経科学研究所神経発達・再生医学分野、2. 名古屋市立大学大学院医学研究科新生児・小児医学分野、3. 生理学研究所神経発達・再生機構研究部門 Sakura Gokenya¹, Koya Kawase^1,2, Akira Ito¹, Masato Sawada^1,3, Osuke Iwata², Shinji Saitoh², Kazunobu Sawamoto^1,3 1. Dept Dev Regen Neurobiol, Inst Brain Sci, Nagoya City Univ Grad Sch Med Sci, Nagoya, Japan, 2. Dept Pediat Neonatol, Nagoya City Univ Grad Sch Med Sci, Nagoya, Japan, 3. Div Neural Dev Regen, NIPS, Okazaki, Japan For mammalian individuals including humans, birth is one of the most drastic changes in their environment. Since preterm infants have long-lasting neurological disabilities, the timing of birth is thought to critically regulate normal brain development and functions. During embryonic brain development, radial glial cells are embryonic neural stem cells (NSCs) and actively produce new neurons. Immediately after birth in rodents, radial glial cells rapidly disappear by transforming into postnatal NSCs and ependymal cells, leading to the establishment of the specialized neurogenic niche in the postnatal ventricular-subventricular zone (V-SVZ). New neurons generated from NSCs in the postnatal V-SVZ migrate toward the olfactory bulb (OB), where they differentiate into mature interneurons and regulate olfactory functions. Recent studies suggest that even in human infants newly generated neurons migrate from the periventricular region toward the OB and cerebral cortex, suggesting the possibility that these new neurons contribute to the postnatal neural development and functions in the human brain. However, the effect of preterm birth on neurogenesis in the postnatal V-SVZ remains unknown. In this study, we studied neurogenic potential in the postnatal V-SVZ of preterm-birth models in mice. We found that the cellular composition of V-SVZ is changed through postnatal development. In addition, the number of neural progenitor cells in the postnatal V-SVZ is decreased in preterm-birth mice, leading to the decrease in the numbers of immature migrating neurons in the rostral migratory stream and mature interneurons reached in the OB. Taken together, these results suggest that the timing of birth controls the establishment and maintenance of postnatal neurogenesis in the V-SVZ.		2020/9/10　14:00～15:00　オンデマンドB-2 PU2 ミクログリアによる死細胞の貪食は嗅球ニューロンのターンオーバーを調節する Microglial phagocytosis of dying neurons maintains neuronal turnover in the adult olfactory bulb 石戸裕梨¹、澤田雅人^1,2、榑松千紘¹、大石久史³、大村谷昌樹⁴、長田重一⁵、浅野謙一⁶、田中正人⁶、澤本和延^1,2 1. 名古屋市立大学大学院医学研究科脳神経科学研究所神経発達・再生医学分野、2. 生理学研究所神経発達・再生機構研究部門、3. 名古屋市立大学大学院医学研究科病態モデル医学分野、4. 兵庫医科大学遺伝学、5. 大阪大学免疫学フロンティア研究センター免疫・生化学、6. 東京薬科大学生命科学部免疫制御研究室 Yuri Ishido¹, Masato Sawada^1,2, Chihiro Kurematsu¹, Hisashi Oishi³, Masaki Ohmuraya⁴, Shigekazu Nagata⁵, Kenichi Asano⁶, Masato Tanaka⁶, Kazunobu Sawamoto^1,2 1. Dept Dev Regen Neurobiol, Inst Brain Sci, Nagoya City Univ Grad Sch Med Sci, 2. Div Neural Dev Regen, NIPS, 3. Dept Comp Exp Med, Nagoya City Univ Grad Sch Med Sci, 4. Dept Genet, Hyogo Col Med, 5. Lab Biochem Immunol, World Premier Intl Res Ctr, Immunol Front Res Ctr, Osaka Univ, 6. Lab Immune Reg, Tokyo Univ Phar Life Sci In the adult rodent brain, new neurons are generated in the ventricular-subventricular zone and supplied to the olfactory bulb (OB). In the OB, while these new neurons differentiate into mature interneurons, old neurons are eliminated from OB circuits by cell death, contributing to the maintenance of neuronal population and olfactory functions. We have previously reported that empty positions made by neuronal cell death are filled by newly added neurons, suggesting that cell death and subsequent regeneration of neurons are coupled in the adult OB. However, the mechanisms regulating this neuronal turnover in the adult OB are unclear. Microglia are professional phagocytes in the brain and engulf dying cells and unwanted synapses to maintain brain homeostasis. Previous studies suggest that microglia phagocytose apoptotic neural progenitors to maintain neurogenesis in the adult hippocampus. However, the role of microglial phagocytosis of dying cells in neuronal turnover in the adult OB remains unknown. We found that microglia phagocytose dying interneurons in the adult OB. To inhibit microglial phagocytosis of dying neurons, we used MFG-E8^D89E, a dominant-negative form of MFG-E8, which tethers apoptotic cells to microglia to promote phagocytosis. MFG-E8^D89E expression in the OB inhibited both microglial phagocytosis of dying neurons and addition of new neurons, leading to the disruption of olfactory behaviors. Taken together, these results suggest that microglial phagocytosis of dying neurons has an important role in the neuronal turnover and olfactory functions in the adult OB.

2020/9/10　14:00～15:00　オンデマンドB-2 PU3 Glyphosate 急性投与と慢性投与の神経毒性効果の違い The neurodevelopmental toxicity of chronic glyphosate exposure in developing rat cerebellum. 佐竹繁寿¹、二神健¹、トーマスティオンクオンスン¹、のむらようこ²、諫田泰成³、吉田祥子¹ 1. 豊橋技術科学大学、2. クイーンズカレッジニューヨーク市立大学、3. 国立衛生科学研究所 Shigehisa Satake¹, Ken Futagami¹, Kwong Soon Thomas Tiong¹, Yoko Nomura², Yasunari Kanda³, Sachiko Yoshida¹ 1. Toyohashi University of Technology, 2. Queens College, the City University of New York, 3. National Institute of Health Sciences Prenatal chemical exposure is a growing health concern as it can cause a lifelong lasting effect on the psychological and physiological health in both pregnant mother and offspring, which supports the Developmental Origins of Health and Disease (DOHaD) hypothesis. Glyphosate (GLY), the main compound of a broadly applied herbicide, is the negative substance on the Organization for Economic Cooperation and Development (OECD) Test Guidelines; however, the neurodevelopmental safeties of GLY or some metabolites are unknown. The primary herbicidal function of GLY is to inhibit a key plant enzyme, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which participates in the biosynthesis of aromatic amino acids via the shikimate pathway in bacteria, fungi, and plants, so that GLY may have the potential to modify the animal and human gut microbiota. Recently some reports showed that chronic exposure of GLY could induce Parkinson's disease, depression, and ASD. Previously we have shown that acute exposure of 100 or 250 mg/kg-GLY to pregnant rats leads to Purkinje cell death and behavioral disorder in developing cerebellum. In this study, we investigated the effects of prenatal chronic GLY-exposure on the cerebellar cortex in immature offspring. After exposing pregnant rats to GLY-water (approximately 11 mg/kg/day; total dosage is 250 mg/kg) from gestational day 2 (G2) to G23, we observed cerebellar development of the male offspring. GLY-chronic- exposure decreased the number of Purkinje cells and increased microglia in developing cerebellum. Additionally, the growth of offspring was more suppressed than the acute-exposed one so that the GLY-chronic-exposure would have remarkable developmental neurotoxicity. We would estimate its critical dose to neurotoxicity.		2020/9/10　14:00～15:00　オンデマンドB-2 PU4 P2Y1受容体を介したニューロン―アストロサイト―ミクログリア間情報処理機構 Communication among neuron, astrocyte and microglia via P2Y1 receptor. 鈴木秀明¹、繁冨英治¹、平山幸歩¹、佐野史和^1,2、田中謙二³、尾藤晴彦⁴、小泉修一¹ 1. 山梨大・院医・薬理、2. 山梨大・院医・小児、3. 慶應大・医・精神神経、4. 東京大・院医・神経生化 Hideaki Suzuki¹, Eiji Shigetomi¹, Yukiho J Hirayama¹, Fumikazu Sano^1,2, Kenji F Tanaka³, Haruhiko Bito⁴, Schuichi Koizumi¹ 1. Dept. Neuropharmacol. Interdiscipl. Grad. Sch. Med., Univ. Yamanashi, 2. Dept. Pediatr., Interdiscipl. Grad. Sch. Med., Univ. Yamanashi, 3. Dept Neuropsych., Keio Univ Sch Med, 4. Dept. Neurochem., Grad. Sch. Med., Univ. Tokyo Astrocytes receive signals from neurons and also release signals to neurons. To receive neuronal information, astrocytes express a plethora of Gq-protein coupled receptors (GqPCRs). Recent evidence suggests that GqPCR function in astrocytes contributes to brain function. However, due to lack of spatio-temporal information on bidirectional signaling, detailed mechanism in communication between neurons and astrocytes still remains unknown. Among GqPCRs expressed natively in astrocytes, we focused on P2Y1 receptor. P2Y1 receptor has a central role in regulation of Ca^²⁺ signaling in astrocytes. To understand when and how P2Y1 receptor contributes to synaptic function, we used transgenic mice whose astrocyte overexpressed P2Y1 receptor specifically by Tet-off system and imaged activities of neurons and astrocytes simultaneously using dual color of genetically encoded Ca^²⁺indicators (GECI). In CA1 region of acute hippocampal slices, we visualized Ca^²⁺ signals from both cell types. In astrocyte P2Y1 receptor overexpression mice, electrical stimulation of the Schaffer collateral resulted in fast Ca^²⁺ rise in dendrites followed by slow-onset Ca^²⁺ rise in astrocytes. Pharmacological experiments show that neuronal signals were mediated by glutamatergic excitatory synaptic transmission, and the astrocytic ones were mediated by P2Y1 receptor, activated by released ATP presumably from presynaptic sites. Interestingly, microglia depletion caused much larger Ca^²⁺elevation evoked by MRS2365, a P2Y1 receptor agonist in astrocytes, suggesting that microglia should have an important role to control P2Y1 receptor. Overall, our data indicate that astrocytes regulate dendritic activities and reveal dynamic feature of communication between neurons and glia.

2020/9/10　14:00～15:00　オンデマンドB-2 PU5 血液脳関門バリア機能に対するIL-6ファミリーサイトカインの効果 Effects of IL-6 family cytokines on blood-brain barrier function 濵田奨¹、人羅菜津子¹、南雅文¹ 1. 北海道大学 Sho Hamada¹, Natsuko Hitora¹, Masabumi Minami¹ 1. Hokkaido University [Background] The blood-brain barrier (BBB) serves to restrict movement of materials from the circulating blood to the brain. A monolayer of brain microvascular endothelial cells (BMECs) create BBB. IL-6 is one of the soluble factors produced by astrocytes, which are known to regulate BBB functions.IL-6 receptors include two types, membrane-bound and soluble receptors, which are known to couple to the different intracellular signaling each other. Our laboratory previously reported that treatment with leukemia inhibitory factor (LIF) and oncostatin M (OSM), both of which are IL-6 family members,decreased BBB function. However, details of the effects of IL-6 remain unclear. In this study, we aimed to clarify the effects of treatment with IL-6 and co-treatment with IL-6 and its soluble receptor (IL-6+sIL-6R) on BBB function. [Methods] C57/B6 mice (3 – 4 weeks old) were used. In vitro BBB model was prepared by seeding BMECs onto Transwell inserts, and treated with IL-6, IL-6+sIL-6R, LIF or OSM (100 ng/ml each).Barrier function was evaluated by measuring transendothelial electrical resistance (TEER). [Results and Discussion] IL-6 and IL-6+sIL-6R, as well as LIF and OSM, decreased the BBB function. Among these cytokines, OSM showed the strongest effect. IL-6, IL-6+sIL-6R and LIF decreased the BBB function to the same extent. These results suggest that IL-6 family cytokines negatively regulate the BBB function. We are planning further analyses of the effects of IL-6 family cytokines on BBB function using a FITC-dextran (FD4) permeability test and immunostaining for tight junction proteins.		2020/9/11　14:00～15:00　オンデマンドB-2 PU6 成体脳を移動する新生ニューロンにおける成長円錐の形態と動態 Dynamic change in growth cone morphology in adult-born migrating neurons 高木佑真¹、澤田雅人^1,2、中嶋智佳子¹、松本真実^1,2、大野　伸彦^2,3、五十嵐道弘⁴、澤本和延^1,2 1. 名古屋市立大学、2. 生理学研究所、3. 自治医科大学、4. 新潟大学 Yuma Takagi¹, Masato Sawada^1,2, Chikako Nakajima¹, Mami Matsumoto^1,2, Nobuhiko Ohno^2,3, Michihiro Igarashi⁴, Kazunobu Sawamoto^1,2 1. Nagoya City Univ., 2. Natl. Inst. Physiol. Sci., 3. Jichi Med. Univ., 4. Niigata Univ. Growth cone is a highly motile structure and involved in the sensing of various guidance cues to project neuronal processes such as developing axons and dendrites. Appropriate regulation of growth cone dynamics is important for neuronal projection and subsequent synaptic formation in neuronal development and regeneration. Previous studies revealed the ultrastructure and dynamics of growth cone in developing axons. Although migrating immature neurons also possess growth cone at the tip of their leading process, their morphological and dynamic properties are not well understood. In the adult brain, newly born neurons (neuroblasts) produced in the ventricular-subventricular zone (V-SVZ) migrate toward the olfactory bulb through the rostral migratory stream (RMS). In the RMS, these neuroblasts form chain-like cell aggregates to migrate rapidly inside the glial tube. Interestingly, neuroblasts form growth cone to efficiently extend their leading process along their neighboring neuroblasts, leading to their efficient chain migration in the adult brain. However, the morphology and dynamics of growth cone in V-SVZ-derived neuroblasts remains unclear. In this study, we studied the structure and dynamics of growth cone in V-SVZ-derived migrating neuroblasts. Electron microscopic analyses revealed the ultrastructure of neuroblasts and their growth cone in the adult RMS. Furthermore, we established the automatic segmentation method to extract the growth cone morphology using Trainable Weka Segmentation plug-in in ImageJ, and analyzed the growth cone dynamics in cultured V-SVZ-derived neuroblasts. Together, these results suggest that the dynamic change in growth cone morphology is related to efficient migration of V-SVZ-derived neuroblasts in the adult brain.

2020/9/11　14:00～15:00　オンデマンドB-2 PU7 運動ニューロンにおける新規Olig2結合因子Obp2欠損マウスの表現型解析 Phenotypic analysis of Olig2-binding factor Obp2-deficient mice in motor neurons 目黒雄大¹、備前典久¹、矢野真人¹、矢野佳芳¹、阿部学²、崎村健司²、竹林浩秀¹ 1. 新潟大院・医歯学・神経生物、2. 新潟大・脳研・モデル動物開発 MEGURO YUTA¹, Norihisa Bizen¹, Masato Yano¹, Yoshika Yano¹, Manabu Abe², Kenji Sakimura², Hirohide Takebayashi¹ 1. Div. of Neuro. Anat., Grad. School of Med. and Dent. Sci., Niigata Univ., 2. Department of Animal Model Development,Brain Research Institute.,Niigata Univ. Olig2, a basic helix-loop-helix transcription factor, is essential for the development of motor neurons and oligodendrocytes in the central nervous system. We have identified a novel Olig2 binding factor, Obp2 (Olig2-binding protein 2), and found that Obp2 contributed to the maintenance of neural progenitor cells and oligodendrocyte progenitor cells. However, the roles of Obp2 in motor neurons has remained unclear. In the present study, we generated motor neuron-specific Obp2-deficient (Hb9-Cre; Obp2 cKO) mice and analyzed the phenotypes. Immunohistochemistry and in situ hybridization demonstrated that Obp2 ablation using Hb9-Cre allele did not affect the generation of motor neurons at embryonic stages, however, increased levels of p53 protein, which is a regulator of cell cycle arrest and apoptosis, were observed in the spinal motor neurons immediately after birth. In addition, Obp2 cKO mice showed the decreased number of ChAT-positive motor neurons and motor deficits at 4 months of age. These results suggest that Obp2 is involved in the survival of motor neurons via suppression of the p53 pathway.		2020/9/11　14:00～15:00　オンデマンドB-2 PU8 ジオスゲニンによってアルツハイマー病の記憶障害が回復することに関与する、脳内の内分泌的作用の探索 Exploration of diosgenin-elicited endocrinological effects in the brain relating to memory recovery in Alzheimer's disease 真継理子¹、楊熙蒙¹、中野葵、東田千尋¹ 1. 富山大学和漢医薬学総合研究所神経機能学領域 Noriko Matsugi¹, Ximeng Yang¹, Aoi Nakano, Chihiro Toda¹ 1. Division of Neuromedical Science, Institute of Natural Medicine, Toyama Univ. Our previous study revealed that diosgenin, a plant-derived steroidal sapogenin, improved memory dysfunction and axonal atrophy in the brain of Alzheimer's disease model mice, (5XFAD). It also turned out that diosgenin reduced amyloid plaques and PHF-tau in the 5XFAD mice brain. We, furthermore, identified membrane-associated rapid response steroid-binding protein (1,25D₃-MARRS) as the receptor of diosgenin on the neuron membrane. Diosgenin treatment for only two weeks significantly achieves the cognitive improvement in 5XFAD mice with sever memory impairment. The recovery of memory function was maintained for a long time after quitting dosing. We hypothesized that this potent and sustained effect of diosgenin might due to duality of diosgenin, a direct effect on neurons and an indirect effect on other surrounding or distal cells in the brain mediated by some of secreted factors. Therefore, this study aimed to investigate the existence of beneficial molecule secreted into CSF according to diosgenin treatment and to clarify overall pharmacological effects of diosgenin. Conditioned media of primary cultured neurons treated with Diosgenin or vehicle solution were collected. Each conditioned medium was applied to freshly prepared cortical neurons. After four days of the treatment, lengths of axons and dendrites were quantified by immunocytochemistry. Diosgenin-treated conditioned medium enhanced axonal length and dendritic length. In other experiment, cerebrospinal fluid (CSF) was collected from cisterna magna of 5XFAD mice which were treated with vehicle solution or diosgenin for 18 days. The collected CSFs were separated on SDS-PAGE and analyzed to identify diosgenin treatment-specific CSF factors. In addition, for functional evaluation of diosgenin treatment-specific CSF, primary cultured cortical neurons were treated by medium containing CSF. We are now in the process of analyzing the proteins. We found that diosgenin treatment might stimulate secretion of some beneficial factors at least for neurite formation. More detail analyses are under investigation.

2020/9/11　14:00～15:00　オンデマンドB-2 PU9 うつ様行動を誘発する慢性社会敗北ストレスに対するマウスの感受性決定要因としての海馬ミクログリア及び腸内細菌叢の関与 Possible involvement of hippocampal microglia and gut microbiota in susceptibility to chronic social defeat stress inducing depressive-like behaviors 上村祐介¹、桒垣衣里奈¹、濵野咲佳¹、高畑祐香¹、吉本和佳¹、森戸克弥¹、西村周泰²、高山健太郎¹、高田和幸²、長澤一樹¹ 1. 京都薬科大学衛生化学、2. 京都薬科大学統合薬科学 Yusuke Kamimura¹, Erina Kuwagaki¹, Sakika Hamano¹, Yuka Takahata¹, Waka Yoshimoto¹, Katsuya Morito¹, Kaneyasu Nishimura², Kentaro Takayama¹, Kazuyuki Takata², Kazuki Nagasawa¹ 1. Kyoto Pharmaceutical University Department of Environmental Biochemistry, 2. Kyoto Pharmaceutical University Division of Integrated Pharmaceutical Sciences Psychosocial stress, a major etiology of depression, induces inflammation in the brain hippocampus and alteration of gut microbiota. It is reported that susceptibility for chronic social defeat stress (CSDS) is different between C57BL/6J (B6)- and BALB/c (BALB)-strain mice, but its details are unknown. Here, we compared characteristics of brain hippocampal microglia and gut microbiota between the two mouse strains. For CSDS-loading, a male B6 or BALB mouse was exposed to a male ICR one for 10 min, followed by co-caging in a separated space in a cage using a plastic divider with holes, and this was repeated for 10 days. Depressive-like behaviors were evaluated by a forced swim (FS) test, etc. mRNA expression and numbers of hippocampal microglia were determined by real-time PCR and stereology, respectively. Sequence data regarding V3-V4 region of the 16S rRNA of gut microbiota were analyzed with QIIME2 pipeline, and taxonomy was assigned with the Silva database. CSDS-loading decreased the sociability of both mice, while depressive-like behaviors were developed only in BALB mice, whose hippocampal expression of TNF-α mRNA was increased. In naïve mice, the Iba1-immunoreactive microglial number and CD11b mRNA expression in hippocampus were less and greater, respectively, in BALB mice than in B6 ones. Abundance of Bifidobacterium was significantly decreased in susceptible BALB mice, but not B6 ones, and the abundance in the former was inversely correlated with the immobility time in the FS test. The abundance of Bifidobacterium was greater in naïve B6 mice than in naïve BALB ones. These data indicate that activation status of hippocampal microglia and abundance of Bifidobacterium in the gut might be determinants of susceptibility for CSDS.