Poster

Poster 15 ADHD/ASD/Epilepsy 1 ポスター 15 ADHD/ASD/てんかん1

P15-1 Mitochondrial dysfunction in dopaminergic neurons differentiated from exfoliated deciduous tooth-derived pulp stem cells of a child with Rett syndrome レット症候群患児の乳歯歯髄幹細胞から分化したドーパミンニューロンに認めたミトコンドリア機能障害 Masuda Keiji（増田啓次），加藤大樹，廣藤雄太，廣藤早紀，山座治義，佐藤浩，高山扶美子，野中和明 Section of Oral Medicine for Children, Faculty of Dental Science, Kyushu Univ., Fukuoka, Japan Rett syndrome is an X-linked neurodevelopmental disorder associated with psychomotor impairments, autonomic dysfunctions and autism. Patients with Rett syndrome have loss-of-function mutations in MECP2, the gene encoding methyl-CpG-binding protein 2 (MeCP2). Abnormal biogenic amine signaling and mitochondrial function have been found in patients with Rett syndrome; however, few studies have analyzed the association between these factors. This study investigated the functional relationships between mitochondria and the neuronal differentiation of the MeCP2-deficient stem cells from the exfoliated deciduous teeth of a child with Rett syndrome. An enrolled subject in this study was a 5-year-old girl carrying a large deletion that included the methyl-CpG-binding domain, transcriptional repression domain, and nuclear localization signal of MECP2. Using the single-cell isolation technique, we found that the two populations of MeCP2-expressing and MeCP2-deficient stem cells kept their MECP2 expression profiles throughout the stages of cell proliferation and neuronal differentiation in viro. Neurite outgrowth and branching were attenuated in MeCP2-deficient dopaminergic neurons. MeCP2-deficient cells showed reduced mitochondrial membrane potential, ATP production, restricted mitochondrial distribution in neurites, and lower expression of a central mitochondrial fission factor, dynamin-related protein 1 than MeCP2-expressing cells. These data indicated that MeCP2-deficiency dysregulates the expression of mitochondrial factors required for the maturation of dopaminergic neurons. This study also provides insight into the pathogenic mechanism underlying dysfunction of the intracerebral dopaminergic signaling pathway in Rett syndrome.		P15-2 Need for closure and flexible decision-making in individuals with and without autism spectrum disorder 自閉スペクトラム症における認知完結的欲求と柔軟な意思決定 Fujino Junya（藤野純也）^1,2，鄭志誠^1,2,3,4，板橋貴史¹，青木悠太¹，太田晴久^1,5，久保田学^1,6，磯部昌憲²，橋本龍一郎^1,7，中村元昭^1,8，加藤進昌¹，高橋英彦^1,2 ¹Medical Institute of Developmental Disabilities Research, Showa University, Tokyo, Japan ²Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan ³Institute of Applied Brain Sciences, Waseda University, Saitama, Japan ⁴School of Human and Social Sciences, Tokyo International University, Saitama , Japan ⁵Department of Psychiatry, School of Medicine, Showa University, Tokyo, Japan ⁶National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan ⁷Department of Language Sciences, Graduate School of Humanities, Tokyo Metrop olitan University, Tokyo, Japan ⁸Kanagawa Psychiatric Center, Kanagawa, Japan The need for closure (NFC), a desire for a firm answer and less ambiguity, has a key role in cognitive flexibility. Cognitive inflexibility has been reported in various psychiatric disorders, particularly autism spectrum disorder (ASD), which is clinically characterized by social-interaction difficulties and narrowed interests. Recent studies have also shown that individuals with ASD experience more stress in uncertain situations than do those with typical development (TD). These research findings and clinical observations suggest that NFC is altered in ASD, which plays a key role in cognitive inflexibility. However, to the best of our knowledge, no study has directly investigated NFC in ASD or its association with cognitive inflexibility. In this study, we compared the NFC facets between the TD and ASD groups and investigated the relationship between NFC and cognitive flexibility. This study was approved by the Committee on Medical Ethics of Kyoto University and the institutional review board of the Showa University Karasuyama Hospital. On NFC, individuals with ASD reported higher levels in preference for predictability and closed-mindedness and lower levels in decisiveness compared with those with TD. In addition, these NFC facets were significantly associated with cognitive flexibility in ASD as well as TD groups. The study findings provide further insights into the motivational underpinnings of social cognition and flexible behavior by illustrating the construct of NFC in individuals with ASD.

P15-3 PRKD2 harbors ASD-associated de novo mutations and is involved in the regulation of neurodevelopment 複数の自閉症スペクトラム障害患者にde novo変異が認められるPRKD2は神経発達に関与する Baba Masayuki（馬場優志）¹，松村憲佑¹，中澤敬信^1,2，永安一樹^1,3，笠井淳司¹，田熊一敞^2,4，橋本均^1,4,5,6 ¹Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University ²Department of Pharmacology, Graduate School of Dentistry, Osaka University ³Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University ⁴Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University ⁵Division of Bioscience, Institute for Datability Science, Osaka University ⁶Open and Transdisciplinary Research Initiatives, Osaka University Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social interaction and communication. The molecular mechanisms underlying the behavioral and pathological phenotypes of ASD are still not well understood. Furthermore, there is no effective medications to treat their core symptoms. Recent studies suggest that spontaneous de novo mutations contribute to the risk of ASD and generate large effects on the etiology of ASD. Particularly, it is likely that genes with recurrent de novo possible loss-of-function mutations play key roles in the disease progression. We and others have recently identified ASD-associated de novo mutations in PRKD2. However, the role of PRKD2 and the functional consequences of the identified mutations in the central nervous system remain largely unclear. We found that PRKD2 was highly expressed in the developing central nervous system. We also showed that a knockdown of PRKD2 significantly impaired neurite outgrowth in Neuro2A cells. Consistent with these findings, we found that a knockdown of PRKD2 during embryonic neurodevelopment in vivo inhibited neural migration, increased neural proliferation and decreased neural progenitor differentiation. We then examined the functional consequences of the de novo mutations and found that the de novo mutations decreased the level of autophosphorylation of PRKD2 in HEK293T cells. Our results suggest that PRKD2 regulates neural development in vitro and in vivo and that the identified ASD-associated mutations of PRKD2 impair the kinase activity of PRKD2. Further functional analysis of the de novo mutations in PRKD2 will provide important clues for understanding the molecular pathophysiology of ASD.		P15-4 A new model of attention deficit/hyperactivity disorder (ADHD) related with Arcadlin Arcadlinが関わる新しい注意欠如多動性障害（ADHD）モデル Takemiya Takako（竹宮孝子）¹，川上万留実¹，山形要人²，安田新²，泉光輔¹ ¹Med Res Insti, Tokyo Women's Med Univ, Tokyo, Japan ²Synaptic Plasticity Project, Tokyo Metropoli Insti of Med Sci, Tokyo, Japan Attention deficit/hyperactivity disorder (ADHD) is characterized by hyperactivity, impaired sustained attention, impulsivity, and learning disability concerning with dopamine in prefrontal cortex. Recent studies show that reduction of neuronal excitability via NMDA receptor antagonism is associated with impulsivity and hyperactivity like ADHD. However the mechanisms of NMDA inhibiting ADHD remain unclear. A protocadherin Arcadlin is induced in neurons in the brain by NMDA dependent synaptic activity. Arcadlin regulates synaptic plasticity by facilitating endocytosis of N-cadherin and decreases spine density. The spine density is increased in arcadlin knockout (arcad ko) mice. In this study, we hypothesized that inhibition of Arcadlin was related with the mechanisms of NMDA inhibiting ADHD and investigated whether arcad ko mice revealed ADHD like behavior compared with wild type mice. We monitored mouse behavior in the tests of open field, Y maze, forced swim and dark-light, and automatically analyzed by a computerized tracking system. Statistical analyses were performed using Student’s t test. Traveled distance was significantly long in open field test and Y maze test, and total immobile time was significantly short in forced swim test in arcad ko mice. Moreover, the latency until first entry to light area was significantly short in dark-light test in arcad ko mice. The result suggest hyperactivity and impulsivity in arcad ko mice. On the other hand, arcad ko mice kept the working memory in Y maze test, suggesting that the function of dopamine is not declined in arcad ko mice. We found arcad ko mice showed dopamine-independent ADHD like behavior. Therefore, inhibition of Arcadlin might be related with the mechanisms of NMDA inhibiting ADHD.

P15-5 Analysis of USV calls in the valproic acid induced mouse model of autism バルプロ酸誘発自閉症モデルマウスの超音波発生の解析 Fujisaku Tomoaki（藤咲友朗），傅品悦，辻隆宏，辻知陽 Research Center for Child Mental Development, Kanazawa, Japan Autism spectrum disorder (ASD) is a lifelong condition which is diagnosed by age 8 each year. It appears in 1 out of 68 according to the Center for Disease Control and Preventions (2014) and the characteristic symptoms of this developmental disorder are deficits in social skills, speech and nonverbal communication, and repetitive behaviors. However, ASD characteristic symptoms are shown in the wide variety of range with combination of other symptoms which makes the ASD not a uniform disorder. The accumulating evidences have shown that the cause of ASD is due to the different combinations of genetic and environmental influences. Further studies are necessary to understand the ASD, because there is almost no pharmacological treatment to cure the ASD symptoms.Valproic acid (VPA) is an antiepileptic drug widely used to treat epilepsy and migraine, but shown to increase the risk of malformation, ASD, and mental retardation in the children by the use of VPA during pregnancy. According to these reports, researchers use VPA to create ASD model rodents. The siblings born from VPA-exposed-dams show anxiety-like behavior, social behavior deficit, and cognitive dysfunction which are common symptoms of the ASD. However, all of the behavioral studies have been conducted during adulthood and not during childhood. Here, we examined the ultrasonic vocalization (USV) of the pups induced by separation from dam. The number of USV calls of the VPA-infant was similar to the control up to postnatal day 7, but significant less on postnatal day 11. These results suggest that the onset of the deficit in social behavior may start from early age in VPA exposed pups.		P15-6 ASD- and ADHD-like behaviors of LMTK1-knockout mice LMTK1ノックアウトマウスにおけるASD/ADHD様行動の解析 Takahashi Miyuki（高橋美由紀）¹，杉山亜梨華¹，高橋路佳¹，福田公子¹，Wei Ran¹，安藤香奈絵¹，友村美根子²，久永眞市¹ ¹Dept. of Biol, Tokyo Met. Univ, Tokyo ²Meikai Pharm-Medic. Lab, Meikai Univ. School of Dentistry, Sakado Lemur kinase 1 (LMTK1) is a novel Ser/Thr kinase, which is highly expressed in mammalian brains. We report that LMTK1 regulates axon and dendrite elongation negatively through the transport of Rab11-positive recycling endosomes. Knockdown or knockout of LMTK1 enhances axonal outgrowth and dendrite arborization. LMTK1 prevents overgrowth of axon and dendrites by controlling the supply of membrane components to the tip of neurites. We hypothesized that overgrowth of neurites caused by dysfunction of LMTK1 would result in neurodevelopmental disorders. However, its expression in brains has not been addressed yet. In this study, we examined the expression of LMTK1 in mouse brains and then analysed behaviors of LMTK1- knockout (KO) mice. LMTK1 was expressed in most neurons in brains at postnatal day 5 and its expression increased gradually with aging. To reveal in vivo function of LMTK1, we analysed the brain structure and behaviors of LMTK1 KO mice. The structures of brains appeared normal when observed after Nissle staining but the number of synapses was increased when examined by immunostaining of synaptic proteins. Electron microscopic observation showed the increased synaptic vesicles in presynaptic terminal of LMTK1 KO mouse neurons. Further, dendritic extension was enhanced in cultured cerebellum Purkinje cells of KO mice. LMTK1 KO mice exhibited abnormal behaviors, such as increased activity and repetitive behavior, reduced anxiety and depression-like behavior. These results indicate that LMTK1 plays an important role in dendrite formation and synaptic activity, and its depletion causes behavioral abnormalities similar to autism spectrum disorder (ASD) and attention deficit hyperactivity disorders (ADHD).