誘導、パターン形成 Induction and Pattern Formation
P1-1-49 マウス発達過程における神経特異的分子shati/nat8lの発現変化 Expression of neuron-specific molecule “shati/nat8l” increases with the development in mice ○鷲見和之1, 宇野恭介1, 岩本諒1, 鍋島俊隆2, 古川-日比陽子3, 宮本嘉明1, 新田淳美1 ○Kazuyuki Sumi1, Kyosuke Uno1, Ryo Iwamoto1, Toshitaka Nabeshima2, Yoko Furukawa-Hibi3, Yoshiaki Miyamoto1, Atsumi Nitta1 富山大学大学院医学薬学研究部　薬物治療学研究室1, 名城大学薬学部　地域医療薬局学講座2, 名古屋大学大学院医学系研究科医療薬学講座・医学部附属病院薬剤部3 Department of Pharmaceutical Therapy and Neuropharmacology, Faculty of Pharmaceutical Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama1, Department of Regional Pharmaceutical Care and Science, Meijo University, Nagoya2, Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya3 A novel molecule shati/nat8l has been identified from the nucleus accumbens of mice treated with methamphetamine. We have demonstrated that shati/nat8l depressed the methamphetamine dependence. Recently, we have reported that shati/nat8l-knockout mice reduce social interaction compared with wild type mice. These results have indicated the importance of shati/nat8l in the brain. In another recent report, the role of shati/nat8l in the brain has been revealed N-acetylaspartate (NAA) biosynthetic enzyme aspartate N-acetyltransferase. NAA is expressed in the neurons at relatively high concentrations and, its level is correlated with neurodegenerative disorders. It is important to investigate the distribution and function of shati/nat8l in the central nervous system. However, it is unclear when and where shati/nat8l is expressed in the brain. In this study, we examined the expression pattern of shati/nat8l in the mice brain from embryonic stage to mature stage. Shati/nat8l mRNA signal was detected the amount all brain region of mice by using our in situ hybridization. There were no differences of shati/nat8l mRNA expression regions among 1W, 2W, and 6weeks brain in mice. Moreover, shati/nat8l mRNA expression is overlapped the NeuN immunoreactivity, but not Iba1 and GFAP. Furthermore, HPLC study showed that the contents of NAA in the mature brain were higher than that of embryonic brain or immature brain. These results indicate that shati/nat8l might play an important role as a ubiquitous protein in the matured brain.	P1-1-50 脳の血管形成初期における周皮細胞の変化 Developmental change in pericytes during early angiogenesis in the embryonic brain ○宮川桃子1, 石龍徳2, 内山安男1 ○Momoko Miyakawa1, Tatsunori Seki2, Yasuo Uchiyama1 順天堂大・医・神経生物学・形態学1, 東京医大・組織・神経解剖学2 Dept Cell Biol and Neurosci, Juntendo Univ Sch Med, Tokyo1, Dept Histol Neuroanat Tokyo Med Univ, Tokyo2 Pericytes are known to consist of heterogeneous cell population, and there are no pericyte-specific markers. In chick embryos, polysialic acid-neural cell adhesion molecule (PSA-NCAM)-expressing pericytes are observed around capillaries in parenchyma and on the surface of the caudal telencephalon, diencephalon and rostral mesencephalon at the early stage of angiogenesis, during embryonic day (E) 3.5 to 7. PSA-NCAM is a marker for immature neurons and is known to play an important role in cell migration and axonal growth. To investigate the characteristics of brain pericytes which are labeled by PSA-NCAM expression, expression of various pericyte-markers were studied by immunohistochemistry in the chick embryos from E3.5 to E14. Immuno-reactivity for cytoskeleton proteins such as, desmin, vimentin and &alfa-SMA which were known to be positive in pericyte was observed in capillaries of the embryonic brain. Expression of these markers in pericytes varied with developmental stages and areas. Desmin and vimentin were more strongly expressed in the pericytes of embryos at E6.5 than at E10.5. Expression of desmin was stronger in capillaries located in the brain surface than in the brain parenchyma. Little difference was observed in &alfa-SMA expression among different stages and areas. PSA-NCAM expression was observed in embryos from E3.5 to E6.5 on capillaries in the above-mentioned restricted area. In the capillaries of the brain parenchyma, desmin and vimentin showed similar distribution in cells with long bipolar morphology, and were overspread with &alfa-SMA. At the tip of the growing capillaries, desmin, vimentin, &alfa-SMA and PSA-NCAM were observed in the shape of fine protrusion. The present results suggest that PSA-NCAM is expressed by pericytes of growing capillaries. However, the precise functional correlation between PSA-NCAM and other marker molecules remains to be solved.
P1-1-51 膜電位依存成長円錐誘導の数理モデル A mathematical model of membrane potential dependent growth cone steering ○山田達也1, 池田和司1, 作村諭一2 ○Tatsuya Yamada1, Kazushi Ikeda1, Yuichi Sakumura2 奈良先端大・情報1, 愛知県立大2 Graduate School of Information Science, Nara Institute of Science and Technology, Nara1, School of Information Science and Technology, Aichi Prefectural University, Aichi2 Pathfinding by a neuronal growth cone is an important function for building accurate and complicated neuronal circuit. Recent study found that Sema3A repels the growth cone and the membrane potential is hyperpolarized under natural condition where cGMP concentration is low, whereas growth cone changes the moving direction to the Sema3A source and the membrane potential is depolarized if the cGMP concentration is elevated. Although biochemical signals have been well studied, the role of membrane potential for growth cone steering is still unknown. If influx of sodium or chloride ions changes in response to the local biochemical signals, the membrane potential also changes near the channels and propagates over the whole cell very fast. The potential propagates much faster than the biochemical signals and increases Ca2+ concentration through a voltage-dependent Ca2+ channels (VDCC). These facts suggest that the membrane potential plays a role as a carrier of global information for controlling growth cone steering. To examine this, in the present study we develop the mathematical model of the growth cone including the membrane potential as well as biochemical signals. The model expresses the Ca2+ signal near VDCC over whole growth cone and that occurred at a local space by cGMP-gated Ca2+ channel (CNGC), which is activated by Sema3A exposure. The model prediction shows that the bidirectional steering for Sema3A guidance cue, suggesting that the growth cone uses not only biochemical signals but also electrical one for controlling moving direction.	P1-1-52 コモンマーモセット体細胞の神経細胞への分化転換：遺伝子改変アルツハイマー病モデルマーモセット解析ツールとして Conversion of common marmoset somatic cells into functional neuronal cells:As a tool for analyses of transgenic Alzheimer’s disease model marmoset 井端啓二1, 岡原純子2, 幸田和久1, 赤松和土1, 柚崎通介1, 岡野ジェイムス洋尚1, 佐々木えりか2, 岡野栄之1 ○Zhi Zhou1, Keiji Ibata1, Junko Okahara2, Kazuhisa Kohda1, Wado Akamatsu1, Michisuke Yuzaki1, James Hirotaka Okano1, Erika Sasaki2, Hideyuki Okano1 慶應・医・生理学1, 実中研・マーモセット研究部2 Dept. of Physiolosy., Sch. of Med., Keio Univ.1, Marmoset Research Dept., CIEA2 Alzheimer’s disease (AD) is the most common neurodegenerative disease. Despite of many efforts, however, no transgenic animal models so far have yet properly recapitulated AD phenotypes in a manner similar to humans. Thus, more suitable animal model, especially primate model, is expected. Common marmoset (Callithrix jacchus), a New World primate, is believed to be an ideal animal model for biomedical research due to its similarity in physiological property, higher brain function and drug metabolism with humans. Previously we have reported the generation of transgenic marmosets with germline transmission for the first time, which opened new avenues for generation of human disease model primates (Sasaki et al., 2009). In our study, we aim at the generation and both in vivo and in vitro analyses of transgenic AD model marmoset. Regarding in vitro analyses, however, analyses using primary neuronal culture of the affected area need to sacrifice the individuals and thus not realistic. As a substitute for primary neuronal culture, we focused on the somatic cell reprogramming technology, especially the direct induction technology, which may serve as powerful tools due to its potential that enables analyses in vitro without invasion. Thus, to obtain marmoset neuronal cells from somatic cells, we lentivirally transduced a set of neuronal transcription factors together with synapsin reporter construct into fibroblasts. Morphological changes and synapsin promoter-driven fluorescent protein expression were then observed during induction, which are indicative of the induced neuronal (iN) cells. Furthermore, the functionality of the generated iN cells was supported by the results that they not only showed neuronal gene expression but also exhibited increased intracellular calcium level upon electrical field stimulation, which was tetrodotoxin sensitive. Taken together, these results suggest that marmoset somatic cells can be converted into functional neuronal cells, or iN cells.
P1-1-53 細胞非自律的な機構による fru 発現ニューロンの性差形成の可能性 The possible involvement of non-cell autonomous mechanism in the sex-specific neurite formation in Drosophila central neurons ○加藤貴大1, 佐藤耕世1, 山元大輔1 ○Takahiro Kato1, Kosei Sato1, Daisuke Yamamoto1 東北大学大学院　生命科学研究科　生命機能科学専攻　脳機能遺伝分野1 Division of Neurogenetics, Tohoku Univ Graduate School of Life Sci, Sendai1 Some of the brain neurons in Drosophila exhibit conspicuous sexual dimorphisms, which are produced by the action of sex determination gene cascade. The key player in this cascade is a female determinant protein, Transformer (Tra). Tra is a female-specific splicing factor that, depending on the sex, produces different mRNA species in two target genes, fruitless (fru) and doublesex (dsx), both encoding transcription factors crucial for the neural sex differentiation. In this study, we focus on a group of fru-expressing neurons, mcALa cluster neurons, as they show a striking sex difference in the neurite structure. mcALa neuron somata are located in the suboesophageal ganglion, extending a long axon along the midline to the dorsal-most region of the brain. Additional short arborizations stemming from the axon base are present in male but not female mcALa neurons. These mcALa male-specific arbors form in females that are homozygous for tra1, a loss-of-function tra allele, which is known to completely masculinize a female fly. It is well recognized that sex-determination in Drosophila takes place on a cell-by-cell basis, i.e., the presence of normal tra activity in a cell directs the cell to take on the female-fate. To see whether this is also the case for mcALa male-specific arbors, we generated tra1-mutant mcALa clones in the female brain, with the expectation that these tra1 mutant clones of mcALa develop the male-specific arborizations. Contrary to this expectation, the male-specific arborizations barely formed in tra1-mutant mcALa neurons generated in the otherwise female brain. Our finding indicates that mcALa neurons require some inductive actions from neighbors to develop the male-specific arbors, representing a non-cell autonomous mechanism for neural sex differentiation in Drosophila.

上部に戻る

前に戻る