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2002 Fiscal Year Final Research Report Summary

Investigation of Ca-dependent cellular functions with caged compounds

Research Project

Project/Area Number 12470006
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field General physiology
Research InstitutionOKAZAKI NATIONAL RESEARCH INSTITUTES

Principal Investigator

KASAI Haruo  National Institute for Physiological Sciences, Professor, 生理学研究所, 教授 (60224375)

Project Period (FY) 2000 – 2002
Keywordsglutamate receptor / two-photon excitation / caged compounds / synapse
Research Abstract

Dendritic spines serve as preferential sites of excitatory synaptic connections and are pleomorphic. To address the structure- function relationship of the dendritic spines, we used two-photon uncaging of glutamate to allow mapping of functional glutamate receptors at the level of the single synapse. Our analyses of the spines of CA1 pyramidal neurons reveal that AMPA (α-amino-3-hydroxyl-5-methyl-4-isoxazolep ropionic acid)-type glutamate receptors are abundant (up to 150/spine) in mushroom spines but sparsely distributed in thin spines and filopodia. The latter may be serving as the structural substrates of the silent synapses that have been proposed to play roles in development and plasticity of synaptic transmission. Our data indicate that distribution of functional AMPA receptors is tightly correlated with spine geometry and that receptor activity is independently regulated at the level of single spines.
Insulin secretion from intact mouse pancreatic islets was investigated with two-photon excitation imaging. Insulin granule exocytosis occurred mainly toward the interstitial space, away from blood vessels. The fusion pore was unusually stable with a lifetime of 1.8 seconds. Opening of the 1.4-nanometerdiameter pore was preceded by unrestricted lateral diffusion of lipids along the inner wall of the pore, supporting the idea that this structure is composed of membrane lipids. When the pore dilated to 12 nanometers, the granules rapidly attened and discharged their contents. Thus, our methodology reveals fusion pore dynamics in intact tissues at nanometer resolution.

  • Research Products

    (18 results)

All Other

All Publications (18 results)

  • [Publications] Nemoto, T.: "Sequential-replenishment mechanism of exocytosis in pancreatic acini"Nature Cell Biol. 3. 253-258 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kishimoto, T.: "Ion selectivities of the Ca^<2+> sensors for exocytosis in rat phaeochromoctoma cells"J. Physiol. (Lond.). 533. 627-637 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Tsubamoto Y.: "Hexamminecobalt (III) chloride inhibits glucose-induced insulin secretion at the exocytotic process"J. Biol. Chem.. 276. 2979-2985 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Matsuzaki, M.: "Dendritic spine geometry is critical for AMPA receptors expression in hippocampal CA1 pyramidal neurons"Nature Neuroscience. 4. 1086-1092 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kasai, H.: "Fast and cAMP-sensitive mode of Ca^<2+>-dependent exocytosis in pancreatic β cells"Diabetes. 51. S19-S24 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Takahashi, N.: "Two-photon excitation imaging of pancreatic islets with various fluorescent probes."Diabetes. 51. S25-S28 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Takahashi, N.: "Fusion pore dynamics and insulin granule exocytosis in the pancreatic islet"Science. 297. 1349-1352 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Noda, M.: "Switch to anaerobic glucose metabolism with NADH accumulation in the β-cell model of mitochondrial diabetes : Characteristics of β HC9 cells deficient in mitochondrial DNA transcription"J Biol. Chem.. 277. 41817-41826 (2002)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kasai, H.: "Structure-stability-function relationships of dendritic spines"Trends in Neurosciences. (in press).

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Nemoto, T.: "Sequential-replenishment mechanism of exocytosis in pancreatic acini"Nature Cell BioL. 3. 253-258 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Kishimoto, T.: "Ion selectivities of the Ca2+ sensors for exocytosis in rat phaeochromocytoma cells"J. Physiol. (Lond.). 533. 627-637 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Tsubamoto, T.: "Hexamminecobalt (III) chloride inhibits glucose-induced insulin secretion at the exocytotic process"J. Biol. Chem.. 276. 2979-2985 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Matsuzaki, M.: "Dendritic spine geometry is critical for AMPA receptors expression in hippocampal CA1 pyramidal neurons"Nature Neuroscience. 4. 1086-1092 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Kasai, H.: "Fast and cAMP-sensitive mode of Ca^<2+>-dependent exocytosis in pancreatic β cells"Diabetes. 51. S19-S24 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Takahashi, N.: "Two-photon excitation imaging of pancreatic islets with various fluorescent probes"Diabetes. 51. S25-S28 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Takahashi, N.: "Fusion pore dynamics and insulin granule exocytosis in the pancreatic islet"Science. 297. 1349-1341 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Noda, M.: "Switch to anaerobic glucose metabolism with NADH accumulation in the β -cell model of mitochondrial diabetes : Characteristics of β HC9 cells deficient in mitochondrial DNA transcription"J Biol. Chem.. 277. 41817-41823 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Kasai, H.: "Structure -stability-function relationships of dendritic spines"Trends in Neurosciences. in press.

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2004-04-14  

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