光学的計測と全胚遺伝子導入法を用いた初期胚中枢神経系における新規脱分極波の解析

• Project/Area Number: 14704074
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Neuroscience in general
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: 佐藤 容子 東京医科歯科大学, 大学院・医歯学総合研究科, 講師 (70251501)
• Project Period (FY): 2002 – 2004
• Project Status: Completed (Fiscal Year 2004)
• Budget Amount: ¥29,120,000 (Direct Cost: ¥22,400,000、Indirect Cost: ¥6,720,000); Fiscal Year 2004: ¥8,320,000 (Direct Cost: ¥6,400,000、Indirect Cost: ¥1,920,000); Fiscal Year 2003: ¥9,490,000 (Direct Cost: ¥7,300,000、Indirect Cost: ¥2,190,000); Fiscal Year 2002: ¥11,310,000 (Direct Cost: ¥8,700,000、Indirect Cost: ¥2,610,000)
• Keywords: depolarization wave / 光学計測 / 膜電位感受性色素 / 鶏胚 / gap junction / NMDA receptor / ラット胚 / 学計測

Research Abstract

ニューロン電位活動の光学的多領域同時計測法を用いた脊椎動物中枢神経系の機能発生・機能形成・機能構築過程についての解析の過程で、脳神経・脊髄神経などの刺激によって、標本内の広範囲にわたって伝播する脱分極波(depolarization wave)が誘発されることを見いだした。このdepolarization waveは、これまでの報告には全く例がない数々の新しい特性を備えており、限局した領域の特定のニューロン群/シナプスに関して想定されていた従来のactivity-dependent developmental regulationとは異なった働きをもつ重要な発生シグナルとして機能しているものと考えられた。
本年度は、主としてラット胚を対象に解析を行い、depolarization waveの時空間発現パターンと、depolarization waveの伝播メカニズムについて、鶏胚とは異なる独自の特性が見られるかどうかを調べた。
(1)depolarization waveは、ラット胚でも脳幹、脊髄、中脳、小脳、間脳、大脳など、中枢神経系のほぼ全領域にわたって広範に伝播することが示された。しかし、鶏胚では孵卵8日の発生段階で、小脳領域に著明なwaveが観察されたのに対し、ラット胚では、ほぼ同じ発生段階に相当する胎生16日において、小脳領域でのwaveの発現はそれほど顕著ではなかった。この相違は、神経細胞の形態学的な分化・発生過程の違いに起因するものと考えられる。
(2)ラット胚におけるdepolarization waveは、NMDA receptorとGABA-A receptorのblockerに対する感受性が最も大きく、その他にも、non-NMDA receptor、nichotinic-Ach receptor、glycine receptorなど、いくつかの神経伝達物質/受容体が協調的に働いていることが明らかとなった。また、waveはgap junction blockerによっても著明に抑制され、鶏胚と同じくgap junctionとchemical synapseの双方が絡み合ったdual networkによって伝播することが示唆された。gap junctionを構成するconnexinのsubtypeを調べるために、connexin immunohistochemistryを行ったところ、connexin 26とconnexin 32が、胎生16日の脳幹で著明に発現していることが明らかとなった。

Research Products

• [Journal Article] Functional representation of the finger and face in the human somatosensory cortex : Intraoperative intrinsic optical imaging. (2005)
  • Author(s): Sato et al.
  • Journal Title: NeuroImage (in press)
  • NAID: 130007039125
• [Journal Article] Optical mapping of the functional organization of the rat trigeminal nucleus : Spatial and temporal dynamics of sensory information transfer during embryogenesis. (2004)
  • Author(s): Momose-Sato et al.
  • Journal Title: Journal of Neuroscience 24 Pages: 1366-1376
• [Journal Article] Optical survey of neural circuit formation in the embryonic chick vagal pathway. (2004)
  • Author(s): Sato et al.
  • Journal Title: European Journal of Neuroscience 19 Pages: 1217-1225
  • NAID: 130005446923
• [Journal Article] Optical mapping reveals developmental dynamics of Mg^<2+>-/APV-sensitive components of glossopharyngeal glutamatergic EPSPs in the embryonic chick NTS. (2004)
  • Author(s): Sato et al.
  • Journal Title: Journal of Neurophysiology 92 Pages: 2538-2547
• [Journal Article] Optical detection of neural function in the chick visual pathway in the early stages of embryogenesis. (2004)
  • Author(s): Miyakawa et al.
  • Journal Title: European Journal of Neuroscience 20 Pages: 1133-1144
• [Journal Article] Optical detection of convergent projections in the embryonic chick NTS. (2004)
  • Author(s): Sato et al.
  • Journal Title: Neuroscience Letters 371 Pages: 97-101
• [Journal Article] 神経興奮と神経回路網の形成 (2004)
  • Author(s): 佐藤容子
  • Journal Title: Clinical Neuroscience 22 Pages: 1214-1214
• [Book] Light Scattering Imaging of Neural Tissue Function (2005)
  • Author(s): Sato et al.
  • Publisher: The Human Press Inc (in press)
• [Book] Light Scattering Imaging of Neural Tissue Function (2004)
  • Author(s): Sato et al.
  • Total Pages: 25
  • Publisher: Research Signpost
• [Publications] Momose-Sato, Y.et al.: "Optical analysis of large-scale depolarization waves in the embryonic brain : a dual network of gap junctions and chemical synapses."Journal of Neurophysiology. 89. 600-614 (2003)
• [Publications] Momose-Sato, Y.et al.: "Depolarization waves in the embryonic CNS triggered by multiple sensory inputs and spontaneous activity : Optical imaging with a voltage-sensitive dye."Neuroscience. 116. 407-423 (2003)
• [Publications] Sato, K., Momose-Sato, Y.: "Optical detection of developmental origin of synaptic function in the embryonic chick vestibulocochlear nuclei."Journal of Neurophysiology. 89. 2315-3224 (2003)
• [Publications] Miyakawa, N.et al.: "Optical analysis of acute spontaneous epileptiform discharges in the in vivo rat vivo rat cerebral cortex."NeuroImage. 18. 622-632 (2003)
• [Publications] Sasaki, S.et al.: "Postnatal changes in intrinsic optical responses to peripheral nerve stimulation in the in vivo rat spinal cord."NeuroImage. 20. 2126-2134 (2003)
• [Publications] Momose-Sato, Y.et al.: "Optical mapping of the functional organization organization of the rat trigeminal nucleus : Spatial and temporal dynamics of sensory information transfer during embryogenesis."Journal of Neuroscience. (in press). (2004)
• [Publications] Sato, K.et al.: "Optical survey of neural circuit formation in the embryonic chick vagal pathway."European Journal of Neuroscience. (in press). (2004)
• [Publications] Miyakawa, N.et al.: "Keio University International Symposia for Life Sciences and Medicine Vol.11,The Neural Basis of Early Vision."Springer-Verlag. 5 (2003)
• [Publications] Sato, K.et al.: "Light Scattering Imaging of Neural Tissue Function."The Humana Press Inc(in press). (2004)
• [Publications] Sato, K. et al.: "Intraoperative intrinsic optical imaging of neuronal activity from subdivisions of the human primary somatosensory cortex"Cerebral Cortex. 12. 269-280 (2002)
• [Publications] Sato, K. et al.: "Optical approaches to functional organization of glossopharyngeal and vagal motor nuclei in the embryonic chick hindbrain"Journal of Neurophysiology. 88. 383-393 (2002)
• [Publications] Sato, K. et al.: "Developmental organization of the glossopharyngeal nucleus in the embryonic chick brainstem slice as revealed by optical sectioning recording"Neuroscience Letters. 327. 157-160 (2002)
• [Publications] Sasaki, S. et al.: "Optical imaging of intrinsic signals induced by peripheral nerve stimulation in the in vivo rat spinal cord"NeuroImage. 17. 1240-1255 (2002)
• [Publications] Momose-Sato, Y et al.: "Optical analysis of large-scale depolarization waves in the embryonic brain : a dual network of gap junctions and chemical synapses"Journal of Neurophysiology. 18. 600-614 (2003)
• [Publications] Momose-Sato, Y. et al.: "Depolarization waves in the embryonic CNS triggered by multiple sensory inputs and spontaneous activity : optical imaging with a voltage-sensitive dye"Neuroscience. 116. 406-423 (2003)
• [Publications] Miyakawa, N. et al.: "Optical analysis of acute spontaneous epileptiform discharges in the in vivo rat cerebral cortex"NeuroImage. (in press). (2003)
• [Publications] Momose-Sato, Y. et al.: "Recent Research Developments in Membrane Biology"Research Signpost (in press). (2003)
• [Publications] Sato, K. et al.: "Light Scattering Imaging of Neural Tissue Function"The Humana Press Inc (in press). (2003)