線虫 Caenorhabditis elegans の感覚応答と学習を制御する機構  [in Japanese] Regulatory mechanisms of neural circuits and molecular pathways in innate and learned behaviors in Caenorhabditis elegans  [in Japanese]

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Abstract

線虫<I>Caenorhabditis elegans</I>はわずか302個のコンパクトな神経系を持つ。その構造は脊椎動物や昆虫などの脳と大きく異なるが,そこで働く神経回路の様式や分子経路は種を超えて共通したものが多くみられる。線虫は,餌の匂いへの誘引行動や侵害刺激からの忌避行動など,様々な外部刺激に対する応答を示す。さらに,個体群密度や餌の有無など複数の情報を統合し記憶することで,状況に適した行動パターンを選択する。同種他個体から放出される線虫フェロモンにより個体群密度の認識がなされており,フェロモンの作用は幼虫期の発生や,社会性行動,学習など多岐に渡る。学習により後天的に獲得される行動には,インスリン様シグナル伝達やモノアミンシグナル伝達などの種を超えて保存された重要な分子経路が働く。線虫は,遺伝学的解析に有用なモデル生物として古くから用いられてきたが,近年ではそれに加えて神経活動のイメージングによる生理学的な解析も広く行われている。本稿では,線虫の神経系の構造を概説し,化学物質に対する感覚応答や記憶学習を制御する神経回路と分子機構について紹介したい。

  The nervous system of the nematode <I>Caenorhabditis elegans</I> is comprised of 302 neurons. Although the structure of the nervous system is quite different from that of vertebrates or insects, many evolutionally conserved molecules are used in the neural circuits. <I>C. elegans</I> use chemosensation to survive in a continuously changing environment. They migrate to comfortable places by smelling for bacterial food and approaching the source of the smell. They also sense noxious stimuli, such as toxic chemicals and mechanical stimuli, and avoid them. Some of the chemotaxis responses are altered by prior chemical exposure in a given context (i. e., high population density, bacterial infection, and food status). Sugar derivatives termed ascarosides are continuously secreted from <I>C. elegans</I> and used as mediators of population density information in the plasticity of chemotaxis response. Evolutionally conserved molecules, such as components of insulin and monoamine signaling pathways, function in neural circuits to regulate chemotaxis plasticities.<BR>  <I>C. elegans</I> has been used as a useful model animal not only in molecular genetics studies but also in physiological studies using live imaging of neurons. In this review, I introduce the overall structure of the nervous system and regulatory mechanisms of neural circuits and molecular pathways in chemical sensation and information processing to generate an appropriate sensory response.

Journal

  • Hikaku seiri seikagaku(Comparative Physiology and Biochemistry)

    Hikaku seiri seikagaku(Comparative Physiology and Biochemistry) 28(2), 231-239, 2011-07-30

    THE JAPANESE SOCIETY FOR COMPARATIVE PHYSIOLOGY AND BIOCHEMISTRY

References:  51

Codes

  • NII Article ID (NAID)
    10029409368
  • NII NACSIS-CAT ID (NCID)
    AN10391932
  • Text Lang
    JPN
  • Article Type
    REV
  • ISSN
    09163786
  • NDL Article ID
    11202511
  • NDL Source Classification
    ZR4(科学技術--生物学--動物)
  • NDL Call No.
    Z18-1651
  • Data Source
    CJP  NDL  J-STAGE 
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