Poster

Poster 23 Stress/PTSD ポスター 23 ストレス/PTSD

P23-1 Inflammatory markers and their possible effects on cognitive function in women with posttraumatic stress disorder PTSD女性患者における炎症マーカー：炎症の亢進が認知機能低下に影響を与える可能性 Imai Risa（今井理紗）¹，堀弘明²，伊藤真利子²，林明明²，丹羽まどか²，井野敬子¹，小川成¹，関口敦²，松井三枝³，功刀浩⁴，明智龍男¹，加茂登志子⁵，金吉晴² ¹Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. ²Department of Behavioral Medicine, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan ³Department of Clinical Cognitive Neuroscience, Institute of Liberal Arts and Science, Kanazawa University, Kanazawa, Japan ⁴Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan ⁵Wakamatsu-cho Mental and Skin Clinic, Tokyo, Japan. Posttraumatic stress disorder (PTSD) has been associated with increased inflammation. Another key feature of PTSD is compromised function in wide-ranging cognitive domains. Increased peripheral inflammation can contribute to cognitive dysfunction, although this relationship has not been studied in patients with PTSD. We examined blood inflammatory markers in adult patients with PTSD compared to healthy controls taking account of potentially confounding effects of childhood maltreatment and comorbid major depressive disorder (MDD), and explored the association between inflammation and cognition. We enrolled 40 women with PTSD and 65 healthy control women. Diagnoses were made based on DSM-IV. History of childhood maltreatment was assessed using the Childhood Trauma Questionnaire (CTQ). Cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Blood samples were collected for the measurement of 5 inflammatory markers including interleukin-6 (IL-6), soluble IL-6 receptor, interleukin-1β, high-sensitivity tumor necrosis factor-α, and high-sensitivity C-reactive protein. Written informed consent was obtained after description of the study. Participants were assured of the anonymity. Compared to controls, patients with PTSD showed significantly higher IL-6 levels and lower scores on all RBANS domains. IL-6 levels in patients were not significantly associated with the presence/absence of comorbid MDD or CTQ scores. IL-6 levels in patients were significantly negatively correlated with RBANS visuospatial construction, language, attention and total score. These results suggest that elevated IL-6 is associated with PTSD and that the lower cognitive function in PTSD may be due at least partly to increased inflammation.		P23-2 The role of glucocorticoid receptor in the induction and the prevention of the hippocampal abnormalities in an animal model of PTSD PTSDモデルラットにおけるグルココルチコイド受容体を介した海馬神経細胞のアポトーシスとその予防 Araki Motoaki（荒木基亮）¹，淵上学¹，宮城達博¹，森信繁² ¹Department of Psychiatry, Hiroshima University, Hiroshima, Japan ²Kibi International University, Okayama, Japan Posttraumatic stress disorder (PTSD) is a representative stress-related mental disorder associated with an intricate biological and psychological symptom profile. Numerous clinical studies of PTSD demonstrates the functional and morphological abnormalities in the hippocampus after exposure to life-threatening trauma, such as the enhanced negative feedback of the HPA axis, hippocampal atrophy, and fear memory extinction. In this context, it is worthwhile to examine the alteration of hippocampal gene expression through glucocorticoid receptor (GR) in an animal model of PTSD to elucidate the pathophysiology of PTSD. We used a single prolonged stress (SPS) paradigm, which mimic the pathophysiological abnormalities and behavioral characteristics of PTSD including the impaired extinction of fear memory. We first examined whether SPS changed the nuclear levels of GR in the rat hippocampus by Western blot, and found a significant increase 2 h after SPS. Subsequent analyses by ChIP-qPCR and RT-PCR revealed that SPS increased the binding of GR to the glucocorticoid response element (GRE) at the promoter of the Bcl-2 gene. Correspondently, we found the decreased expression of Bcl-2 mRNA in the hippocampus of SPS rats. Based on these findings, it is plausible that the activation of hippocampal apoptotic pathway through the increased binding of GR to the GRE may be induced by severe trauma, and may be consequently involved in the pathophysiology of PTSD. We are now examining the apoptotic changes in the hippocampus of SPS rats using TUNEL staining. In addition, we will examine the preventive effect of GR antagonist mifepristone on the impaired fear extinction, changes in the hippocampal expression of apoptosis-associated genes, and the hippocampal apoptosis in SPS rats.

P23-3 Chemogenetic activation of medial prefrontal cortex excitatory neurons alleviated the impaired fear extinction of an animal model of PTSD 内側前頭前野の神経活動亢進はPTSDモデルラットの恐怖記憶の消去障害を改善する Omura Jun（大村淳）¹，淵上学¹，荒木基亮¹，宮城達博¹，森信繁² ¹Dept. of Psychiatry. Hiroshima University. Hiroshima. Japan ²Kibi International University. Okayama. Japan Although the impaired extinction of fear memory (EFM) is one of the hallmark symptoms of posttraumatic stress disorder (PTSD), the precise mechanisms of impaired EFM are unknown and effective pharmacological interventions have not yet been developed. A growing evidence shows that the activation of infralimbic cortex (IL) predicts successful fear extinction, whereas functionally disrupting this region impairs extinction. We used a single prolonged stress (SPS) paradigm, which mimics the pathophysiological abnormalities and behavioral characteristics of PTSD including the impaired EFM. This study was undertaken to examine whether chemogenetic activation (CA) of mPFC excitatory neurons alleviated the impaired EFM in SPS. The CA was conducted by administration of clozapine-N-oxide (CNO) to activate virally delivered CamKII alpha-hM3Dq-DREADD in mPFC excitatory neurons, and the behavioral effect was examined using contextual fear conditioning. In addition, the effects of CA on the neuronal activity in sham and SPS rats were measured by multi-unit extracellular recording. The CA of IL, but not PL, just before extinction training significantly decreased freezing during the extinction training and extinction test in sham rats, whereas this enhancement of EFM was only seen during the extinction test in SPS rats. Electrophysiological study revealed that the induction of neuronal activation by CA in IL of SPS rats was smaller than that of sham rats, though basal activity (without CA) in SPS rats was almost equal to that in sham. Our results indicates that the decreased excitatory tone in IL might be involved in the mechanism of the impaired Ext in SPS, and the simultaneous treatment with neuronal activation and exposure therapy may be effective in the treatment of PTSD.		P23-4 Juvenile stressed mice showed behavioral abnormalities, resembling those seen in neuropsychiatric disorders 幼少期にストレスを受けたマウスは精神疾患様の行動異常を示す Ueno Hiroshi（上野浩司）¹，末光俊介²，岡本基³，石原武士² ¹Dept. of Med Tech, Kawasaki Univ. of Med. Welf ²Dept. of Psych., Kawasaki Med Sch ³Dept. of Med Tech., Grad Sch. of Health Sci., Okayama Univ Many neuropsychiatric disorders are diagnosed at puberty. However, the cause of the onset remains unclear. It has been reported that the onset of neuropsychiatric disorders such as anxiety, neurosis, depression, post-traumatic stress disorder (PTSD), and schizophrenia are associated with stress exposure during adolescence. We aimed to clarify the effects of juvenile stress on behavior and on the central nervous system. We investigated behavioral abnormalities of chronically-stressed mice during adolescence and the effect of juvenile stress on parvalbumin-positive interneurons (PV neurons) and WFA-positive perineuronal nets (PNNs), which are associated with vulnerability and plasticity in the mouse brain. We discovered that juvenile stress causes increased activity, depressive-like behavior, and social deficits in mice. Furthermore, we revealed that PNNs surrounding PV neurons cause dysplasia. These results suggest that juvenile stress affects the development of the mouse brain and causes behavioral abnormalities different from those seen in the case of stressed mature mice. Juvenile individuals are more sensitive and respond differently to stress than mature individuals.

P23-5 MicroRNA profiling of the ventral hippocampus in stress-resilient and stress-susceptible mice ストレス対処行動におけるマイクロRNAの役割の解析 Higuchi Naoko（樋口尚子），内田周作，山形弘隆，關友恵，古林亜由美，原久美子，中川伸，渡辺義文 Yamaguchi University MicroRNAs (miRNAs) are small noncoding RNA molecules that regulate gene expression post-transcriptionally. MiRNAs play an important role in structural and synaptic plasticity and may contribute to the development of depression and its treatment. We previously reported that chronic stress downregulates hippocampal miRNA-124 and that this is associated with depression-like behavior. To further understand the effects of chronic stress episodes on the miRNA-mediated gene network, we measured miRNAs levels in the ventral hippocampus of two strains of mice, each of which demonstrate different behavioral responses to stress. C57BL/6J (B6) and DBA/2 (DBA) mice were subjected to subchronic social defeat stress (smSDS) episodes. These episodes consisted of brief confrontations with aggressive male mice over a period of 5 days. Two days after the last smSDS session, we carried out a social interaction test to evaluate their depression-like behaviors. We found that stressed B6 mice show normal sociality, whereas DBA mice exposed to smSDS exhibit a significantly less social interaction than non-defeated DBA mice. Thus, we developed B6 and DBA mice as stress-resilient and stress-susceptible strains, respectively. We then performed small RNA-seq analysis to measure miRNA levels within ventral hippocampus in stressed and non-stressed B6 and DBA mice. Small RNA-seq data revealed a unique change in miRNA expression between stress-resilient B6 and stress-susceptible DBA mice. Pathway analysis indicated that the both p38 MAPK and Wnt signaling pathways are strongly associated with stress susceptibility. This study suggests that miRNA expression, influenced by genetic and environmental factors, may contribute to behavioral responses to stress.		P23-6 Correlation between social defeat stress-induced prefrontal serotonergic abnormalities and anxiety-like behavior 社会的敗北ストレスによる大脳皮質前頭前野セロトニン神経系の機能異常と不安様行動との相関性 Araki Ryota（荒木良太）¹，平城陽介¹，田中佑樹¹，田中絵理¹，永峰佑悟¹，吾郷由希夫²，矢部武士¹ ¹Laboratory of Functional Biomolecules and Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University ²Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Osaka University Low serotonin (5-HT) level in the synaptic cleft is generally thought to play a causal role in the pathophysiology of anxiety and depression, because antidepressants which increase extracellular 5-HT levels relieve symptoms of these diseases. However, the low 5-HT hypothesis has some problems such as treatment-resistant anxiety/depression, suggesting that low 5-HT level is not a common symptom in patients with anxiety or depression. To investigate serotonergic abnormalities associated with symptoms of anxiety or depression, in this study, we examined 5-HT turnover and neurotransmission in the several brain regions of social defeat stress model mice. Seven-week-old male C57BL/6J mice were submitted to social defeat stress for 10 consecutive days (Days 1-10). One day after the last social defeat session (Day 11), the social interaction test was performed. Measurement of monoamine turnover, extracellular monoamine levels, locomotor activity and the number of open arms entries in the elevated plus maze were performed at Days 12-17. Serotonin turnover was increased in the prefrontal cortex of the stressed mice. By contrast, 5-HT turnover were decreased in the dorsal raphe nucleus. In the prefrontal cortex, basal extracellular 5-HT levels were also increased in the stressed mice. However, high potassium- or fluoxetine-induced 5-HT releases were decreased. These abnormalities of prefrontal serotonergic system of the stressed mice were correlated with the decreased number of open arm entries in the elevated plus maze, but not social avoidance behavior in the social interaction test. These findings suggest that the abnormalities of prefrontal serotonergic function may induce anxiety-like behavior such as the decreased number of open arm entries.

P23-7 Microarray analysis of gene expression in the prefrontal cortex in social defeat stress 反復社会挫折ストレスにおける前頭前皮質遺伝子発現の検討 Yu Zhiqian（兪志前）^1,2，小野千晶¹，坂井舞¹，富田博秋^1,2 ¹Dept. Disaster Psychiariy. IRIDeS. Tohoku Univ. ²ToMMo. Tohoku Univ. Depression is a mental disorder that affected a large proportion of the population, which is more prevalent in females. Etiology includes environmental and genetic factors, but the responsible genes have not to be identified. Although several functional imaging and genomic studies directly showed the evidence of prefrontal cortex (PFC) abnormalities in patients with depression, the role of genomic mechanism in PFC is poorly understood. The social defeat is widely used as an animal model for depression in neuroscience research. Herein, we assessed the effects of social defeat stress followed with social interaction as an environmental factor on gene expression profiles of PFC in the resilient and susceptible mice by microarrays. Gene ontology analysis was used to investigate molecular and cellular pathways potentially involved in depression-linked behavior. We tested several hypotheses of metal diseases pathologies and their molecular impact, including changes the candidate genes, or existence of subgroups male and female mice, and the possibility of common biological pathways being affected the behavior deficits. Furthermore, using real-time PCR, we found the hormone-associated molecular differences between males and females, which significantly increased in females with depression-linked behavior compared with female controls. Oure results suggest a pathology below the hormone alteration in PFC relevant to the pathogenesis of depression in a gender-specific manner.		P23-8 Effect of EPA on PTSD like behaviors of an animal model for PTSD in rats using a shuttle box エイコサペンタエン酸（EPA）がシャトル箱法による心的外傷後ストレス障害（PTSD）モデルラットのPTSD様行動に与える効果 Shimizu Kunio（清水邦夫）¹，谷知正章²，榎本真悟²，斉藤拓²，竹下省吾²，浅井史穂²，三井由美¹，高橋知久²，古賀農人²，戸田裕之²，長峯正典¹，重村淳²，丹生谷正史³，吉野相英² ¹Division of Behavioral Sciences, National Defense Medical College Research Institute, Tokorozawa, Japan ²Department of Psychiatry, National Defense Medical College, Tokorozawa, Japan ³Department of Psychiatry, Tohoku Medical and Pharmaceutical University, Sendai, Japan 【目的】近年、サバやイワシ等の青魚に豊富に含まれているオメガ3 系脂肪酸のうつ病に対する効果が注目され、PTSDへの効果にも期待が集まっている。中でもEPA（エイコサペンタエン酸）は抗うつ効果と抗PTSD効果に優れるとされており、安全性、易実施性、易受容性の観点から、EPAが豊富な魚等を多く摂る食習慣は、メンタルへルス向上の選択肢として有力な候補である。今回、EPAを多く摂ることが、PTSDを予防し得るか否かについて、シャトル箱法によるPTSDモデルラットを用いて検討した。【方法】ウィスター雄性ラットに対し、4週齢から行動テスト当日の9週齢まで5週間連続で4段階濃度（0%、0.5%、1.5%、3%）のEPA含有餌を自由摂取させ、実験に供した。シャトル箱を用いた従来通りの方法で、7週齢時にPTSDのトラウマに相当する逃避不能ストレス（IS）を負荷し、2週間後の9週齢時に行動テストを実施した。対照群（CT群）としては、トラウマ負荷時にシャトル箱に入れるだけで、逃避不能フットショックストレス（IS）を浴びせない群（sham IS群）を用いた。摂取させた餌のEPA含有濃度（0%、0.5%、1.5%、3%の4種）と、逃避不能フットショックストレスの有無により、ラットは8群に分けられ、各群におけるPTSD様行動の程度を比較することにより、EPAがモデルラットのPTSD様行動に与える効果について検証した。【結果】EPAは、シャトル箱法によるPTSDモデルラットの回避・麻痺症状様の低活動性の行動変化を、EPA含有濃度1.5%と3%で有意に回復させた。一方、EPAは、当該PTSDモデルラットの過覚醒症状様の過活動性の行動変化については、回復させなかった。【考察】行動テストにおける回避数には、学習性の要素が含まれる。一方で、EPAは認知機能の向上等を通じて学習能力を高める可能性がある。これが行動テストにおける回避数の増加に関与した結果、EPAによる回避数の減少効果（PTSDの過覚醒症状回復効果）が相殺された可能性がある。【結論】EPA含有餌がPTSDモデルラットの回避・麻痺症状様の行動を有意に回復させたことは、EPAを多く摂る食習慣がPTSDを予防し得ることを示唆している。