ストレス Stress
P3-1-160 The change of Cocaine- and amphetamine-regulated transcript (CART) expression in the nucleus accumbens after acute restraint stress and its effects on the stress-related behavior in rats ○Hyung Shin Yoon1, Noriko Yamamoto1, Hiroshi Kunugi1 Department of Mental Disorder, NCNP, Tokyo, Japan1 Cocaine- and Amphetamine-regulated Transcript (CART), abundantly expressed in nucleus accumbens (NAcc) in the brain, involved in numerous physiological processes including reinforcing and rewarding effects of psychomotor stimulants, control of feeding, and response to stress. We examined whether mRNA expression of CART in the NAcc changes after acute restraint stress. Rats were divided into 5 groups; 4 groups given restraint stress for 2 hours and one for control. All animals were decapitated either immediately without being stressed or 0.5, 1, 2 and 24 hours after a 2 hour-session of restraint stress. Quantification of the CART mRNA extracted from the NAcc was measured by real-time PCR. As expected, the expression of CART mRNA in the NAcc changed after acute restraint stress in a time-dependent manner. To further examine the role of accumbal CART on the stress-related behavioral response, additional four groups of animals were given CART 55-102 peptides by microinjection or vehicle into the NAcc and their behavior was measured in the open field test. Interestingly, CART 55-102 peptides microinjected into the NAcc changed the anxiety-related behavior in a dose-dependent manner, raising the possibility that CART balance in the NAcc might be important to modulate the stress-related behavior. This work was supported by Grant-in-Aid for JSPS Fellows (24-02218).	P3-1-161 慢性ストレスによるHPA系の機能低下―PVNの神経活動とホルモン分泌― Chronic stress induces the decrase of function for HPA axis - neural activity and hormonal secretion - ○阪井邦正1, 船上仁範1, 宮本朋佳1, 飯田拓真1, 岸本茉希1, 谷口友梨1, 豊田和1, 大浦沙貴子1, 岡部由季1, 和田哲幸1, 長野護2, 重吉康史2, 市田成志1 ○Kunimasa Sakai1, Yoshinori Funakami1, Tomoyoshi Miyamoto1, Takuma Iida1, Maki Kishimoto1, Yuri Taniguchi1, Kazu Toyoda1, Sakiko Ohura1, Yuki Okabe1, Tetsuyuki Wada1, Mamoru Nagano2, Yasufumi Shigeyoshi22, Seiji Ichida1 近畿大・薬・生化学1, 近畿大・医・解剖学2 Div. Biochemistry, Kinki University Faculty of Pharmacy, Osaka1, Dept. Anatomy and Neurobiology, Kinki University Faculty of Medicine, Osaka2 Stress activates hypothalamous-pituitary-adrenal (HPA) axis which is originated from hypothalamic paraventricular nucleus (PVN) in the brain to keep homeostasis in the body, so that induce a various kinds of physiological responses against to the stress. In this study, we investigated various physiological responses by short stress or chronic stress, such as the neural activity in PVN, the concentration of corticosterone (CORT; a stress hormone) and dehydroepiandrosterone (DHEA; an anti-aging hormone) in serum and the expression level of enzymes on the biosynthetic pathway of CORT and DHEA.Male ddY mice weighing 25-30 g were used and bred in every 12-hour light-dark cycle at 24°C. The animals were housed in a temperature- and light-controlled room (24± 1°C with a 12-h light-dark cycle; lights on at 08:00), and were provide access to a standard diet and tap water. Acute stress indicates 4°C cold-exposure for 1 hour. Chronic stress indicates SART stress which is repeatedly exposed to a sudden change in environmental temperature from 24°C to 4°C. Neural activity in PVN was counted the number of c-Fos immunoreactive (c-Fos-IR) cells. The concentration of CORT and DHEA in serum was measured by ELISA. Expression level of CYP17A1 was analyzed by western blot.In acute stressed mice, the number of c-Fos-IR cells and the concentration of CORT in serum were increased, but DHEA concentration in serum was not changed. In SART-stressed mice, CORT and DHEA concentration in serum and expression level of CYP17A1 were reduced. The number of c-Fos-IR cells and CORT and DHEA concentration in serum were not changed by loaded acute stress after chronic stress. SART-stressed mice indicates HPA axis dysfunction, which is decreased neural activity in PVN and are difficult to maintain normal stress responses in homeostasis. It is suggested that chronic stress-induced concentration of DHEA in serum decrease is involved in reduction of neural activity in PVN and CYP17A1 expression level.
P3-1-162 コルチコステロンは、シナプス局在のGRとkinase系を介して海馬神経シナプスを増やす：数理自動解析 Corticosterone induced GR/kinase network-driven rapid spinogenesis in rat hippocampus: Mathematical automated analysis ○小松崎良将1,2,3, 北條泰嗣2,3, 吉屋美雪2,3, 池田宗樹2,3, 向井秀夫2,3, 木本哲也2,3, 川戸佳2,3 ○Yoshimasa Komatsuzaki1,2,3, Yasushi Hojo2,3, Miyuki Yoshiya2,3, Muneki Ikeda2,3, Hideo Mukai2,3, Tetsuya Kimoto2,3, Suguru Kawato2,3 日本大・理工・物理1, 東京大院・総合文化・広域科学2 Dept physics, CST, Nihon Univ, Tokyo1, Grad Sch of Arts and Sci, Univ of Tokyo, Tokyo2, Bioinformatics Project, JST3 Modulation of hippocampal synaptic plasticity by corticosterone (CORT) has been attracting much attention, due to its importance in stress responses. Many studies have investigated the chronic effect of CORT, but rapid effect of CORT in hippocampus is unclear. Here, we investigated effect of CORT(0.1-1 μM), a major glucocorticoid in rat, on the density and head size of dendritic spine which is essential for memory storage processes, in adult male rat hippocampus. Analysis was performed with mathematical automated software Spiso-3D (Mukai et al., Cerebral Cortex, 2011). The application of 1 μM CORT induced a rapid increase in the total density of spines of CA1 pyramidal neurons within 1 h from 0.98 spines/μm to 1.24 spines/μm. CORT increased the density of large-head (0.5-1.0 μm) and middle-head spines, but not small-head (0.2-0.4 μm) spines. Co-application of antagonist of glucocorticoid receptor (GR), abolished the effect of CORT. Blocking NMDA receptors inhibited the CORT effect. Blocking various kinases shows that CORT enhances spinogenesis via MAPK, PKA, PKC, PI3K signaling pathways. These results indicate that CORT drives the signaling pathway including synaptic GR and multiple kinase pathways in hippocampal CA1 neurons (Komatsuzaki et al., 2012 PLoS-ONE).	P3-1-163 慢性ストレスによる不安様行動惹起におけるアクチン重合因子mDiaの役割 A role for mDia, a Rho-regulated actin nucleator, in emotional changes induced by social isolation stress ○出口雄一1, 篠原亮太1裏出良博2, 古屋敷智之1, 成宮周1 ○Yuichi Deguchi1, Ryota Shinohara1, Michael Lazarus2, Yoan Cherasse2, Yoshihiro Urade2, Tomoyuki Furuyashiki1, Shuh Narumiya1 京都大学大学院　医学研究科　神経・細胞薬理学1, 大阪バイオサイエンス研究所2 Department of Pharmacology, Kyoto University Graduate School of Medicine, Japan1, Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Japa2 Neuronal plasticity in the nucleus accumbens (NAc) is thought to mediate emotional changes associated with chronic stress. However, its molecular mechanism remains unknown. Previous experiments using acute brain slices have suggested a role for actin reorganization in activity-dependent neuronal plasticity. mDia, an effector of Rho small GTPases, is critical for de novo synthesis of actin filaments. Among three mDia isoforms, mDia1 and mDia3 are expressed in the mouse brain and are critical for neural development. To address a role for mDia in emotional changes induced by chronic stress in the adulthood, we selectively deleted mDia1 and mDia3 in combination in NAc neurons after neural development, thus preserving normal neural development. Such conditional deletion of mDia reduced the level of anxiety-like behaviors induced by social isolation stress. Furthermore, in primary hippocampal neurons, mDia deficiency affected activity-dependent regulation of synaptic structure and function. Therefore, our study is elaborating a role for de novo synthesis of actin filaments in synaptic regulation in NAc neurons underlying emotional changes induced by chronic stress.
P3-1-164 恐怖記憶は脳内のオメガ3/オメガ6多価不飽和脂肪酸のバランスにより修飾される Fear memory is modulated by balance of omega-3 and omega-6 polyunsaturated fatty acids in the brain ○山田大輔1, 竹尾仁良1,2, 和田圭司1,3, 関口正幸1,3 ○Daisuke Yamada1, Jiro Takeo1,2, Keiji Wada1,3, Masayuki Sekiguchi1,3 国立精神神経セ・神経研・四部1, 日本水産・中央研・健康基盤2, 科学技術振興機構, CREST3 Dept Degenerat Neurol Dis, Natl Inst Neurosci, Natl Cent Neurol Psychiat, Tokyo, Japan1, Health Fund Res, Centr Res Lab, Nippon Suisan Kaisha, Tokyo, Japan2, JST, CREST, Saitama, Japan3 Long chain polyunsaturated fatty acids (PUFAs) are mainly divided into omega-3 and omega-6 compounds, and the balance between these compounds is thought to be important for human health. However, it is obscure whether balance between omega-3 and -6 PUFAs is important for particular brain function. We show that the ratio of omega-3 to omega-6 PUFA (3/6 ratio) in the mouse brain controls emotional fear memory, which is involved in mental illnesses such as anxiety disorders in humans, via modulating endocannabinoid-mediated signaling. Adult mice were fed diets high in omega-3 and low in omega-6 PUFA for 6 weeks. The diets were mainly prepared using krill oil, which is rich in omega-3 PUFA. Then, fear memory was assessed in a contextual fear conditioning test. Fear response 24 h after conditioning was reduced in mice fed a diet containing 5% krill oil (5% krill diet, 3/6 ratio = 0.98), compared with a control diet (3/6 ratio = 0.15). We found a significant increase in the level of brain omega-3 PUFAs and a decrease in the level of omega-6 PUFAs in mice fed 5% krill diet (krill mice). The mean 3/6-ratio in the brain was calculated to be 1.33 and 2.04 for control and 5% krill diets, respectively. Rimonabant, a blocker of CB1 cannabinoid receptors, abolished the fear-attenuating effect of the 5% krill diet. Electrophysiologically, the evoked excitatory post-synaptic current (eEPSC) in basolateral amygdala (BLA) pyramidal neurons of mouse brain slices was recorded to examine depolarization-induced suppression of excitation (DSE). The DSE was enhanced in krill mice compared with that in control mice. The enhancement was abolished by rimonabant. The fear conditioning facilitated the excitability of BLA pyramidal neurons as revealed by a steeper slope of the input-output curve in control mice. However, a significantly smaller increase in the slope was observed in krill mice. Our present findings suggest significance of the brain 3/6-ratio in control of fear memory.	P3-1-165 育児放棄モデル動物が示す新規不安様行動 Novel anxiety-like behavior in a rat model of early life neglect ○國石洋1, 一坂吏志2, 山本未希1, 井久保樹子2, 松田紗依2, 畠義郎1,2 ○Hiroshi Kuniishi1, Satoshi Ichisaka2, Miki Yamamoto1, Natsuko Ikubo2, Sae Matsuda2, Yoshio Hata1,2 鳥取大・院・医・生体高次機能1, 鳥取大・医・生命・神経生物2 Div. Integrative Biosci.,Tottori Univ. Grad. Sch. of Med. Sci., Tottori, Japan1, Div. Neurobiol., Sch of Life Sci., Fac. Med.Tottori Univ., Tottori, Japan2 Postnatal stressful environment induces long-lasting psychiatric influences in later life. Persistent child-abuse, such as emotional neglect, increases the risk of depression and anxiety disorders. Early deprivation (ED) in rodents is a neglect model to study the effects of maternal care on neurological development of infants. We compared depression- and anxiety-like behaviors and HPA responses to stress between ED and control animals. Sprague-Dawley rat pups were separated from their dam and littermates daily for 180 min during postnatal day 2-14. The rats were subjected to behavioral experiments, and assessed for HPA activity after exposure to stress. We found that the leaning-against-high-position-of-wall (LHW) behavior in the open field test increased in ED rats. On the other hand, other measures in the open field test, forced-swim test and corticosterone assay were not significantly different between ED and control rats. Because the relationship between the LHW behavior and anxiety is still not clear yet, I determined whether the behavior is an anxiety-like behavior by measuring the effect of the intensity of illumination and anxiolytic drug on the behavior. The LHW behavior was increased by a high intensity of illumination, and the effect was suppressed by an anxiolytic drug, diazepam. In addition caffeine, which has increased the center time and decreased the thigmotaxis in the open field test, also decreased the LHW behavior. On the other hand, the total leaning-against-wall behavior was not affected in these tests. In the present experiments, the change in the LHW behavior was larger than those in the well known anxiety-like behaviors. These results suggest that the LHW behavior is a new high sensitive anxiety-like behavior, thus could be an useful indicator to assess the effect of early life adverse experience.
P3-1-166 ディーゼル排ガス胎仔期曝露が大脳皮質発達過程に影響を及ぼす Prenatal exposure to diesel exhaust affects developmental process of cerebral cortex ○柳田信也2,3, 落合紘子1, 久保田夏子3, 高野由莉香1, 武田健1,3 ○Hiroko Ochiai1, Shinya Yanagita2,3, Natsuko Kubota3, Yurika Takano1, Ken Takeda1,3 東京理科大院薬1, 東京理科大・理工・教養2, 東京理科大・環境次世代3 Dept pharma, Tokyo Univ of Sci, Chiba, Japan1, Dept Sci and Technol, Tokyo Univ of Sci, Chiba, Japan2, The Center for Environ Health Sci for the Next Generation, Tokyo Univ of Sci, Chiba, Japan3 Recent studies have shown that prenatal exposure to environmental chemicals affected the developmental process in the cerebral cortex, suggesting that environmental factors in the fetal period influence hereditary regulation of neurodevelopmental process. Particularly, we have focused on the health effects of diesel exhaust (DE) known as one of the environmental chemicals, and revealed that prenatal exposure to DE adversely affected central nervous system. In this study, we tried to examine the effects of prenatal exposure to DE on developmental process such as neuronal maturation, apoptosis and formation of cortical layers, which are especially known to be important phenomena in development process of the cerebral cortex. We used immunohistochemical markers to detect cell proliferation and survival (BrdU), immature neurons (DCX), and mature neurons (NeuN), and TUNEL assay to detect apoptosis. Pregnant rats were exposed to DE or normal air (control group) in an inhalation chamber, and then brain samples from male offspring were obtained at 5 days old. In the DE-exposed rats, the densities of BrdU and DCX immunoreactive cells in the cortex were higher than control rats, whereas the densities of NeuN immunoreactive and TUNEL-positive cells were lower than control rats. Furthermore, in the upper layer (II/III), the density of DCX immunoreactive cells of DE-exposed rats was higher than control rats. In the deeper layer (VI), the density of NeuN immunoreactive cells of DE-exposed rats was lower than control rats. These results indicate that prenatal exposure to DE especially increases the number of immature neurons in the upper layer and decreases the number of mature neurons in the deeper layer. In addition, the result of TUNEL assay indicates that prenatal exposure to DE decreases the number of apoptotic cells. These findings suggest that prenatal exposure to DE alters neuronal maturation, apoptosis, and the formation of cortical layers in neurodevelopmental process.

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