• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1998 Fiscal Year Final Research Report Summary

Molecular Genetic Dissection of Synaptic Transmission

Research Project

Project/Area Number 09480237
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 神経・脳内生理学
Research InstitutionGUNMA UNIVERSITY SCHOOL OF MEDICINE

Principal Investigator

KIDOKORO Yoshiaki  Gunma University School of Medicine, Professor, 医学部, 教授 (00053083)

Co-Investigator(Kenkyū-buntansha) SAITOH Minoru  Gunma University School of Medicine, Assistant Professor, 医学部, 助手 (50261839)
YOSHIHARA Motojiro  Gunma University School of Medicine, Assistant Professor, 医学部, 助手 (80222397)
Project Period (FY) 1997 – 1998
Keywordsmutants / SNARE hypothesis / Drosophila / neuronal-synaptobrevin / miniature synaptic currents / cyclic AMP / synaptic vesicle fusion / csp
Research Abstract

For synaptic transmission vesicles in the presynaptic terminal containing neurotransmitter have to fuse to the membrane and release the content to the synaptic cleft. Various proteins are known to be involved in this fusion process. A hypothesis, SNARE hypothesis, is proposed to account for the arrangement of those proteins. We have investigated the molecular mechanism of this process by using Drosophila mutant larvae which lack key molecules.
Neuronal synaptobrevin (n-syb) is vesicle membrane protein and a target of tetanus toxin. In mutant larvae which lack n-syb no nerve-evoked synaptic currents were observed. However, miniature synaptic currents (mSC) remained in lower frequencies. The frequency of mSG's was dependent on external Ca^<2+> concentrations in high potassium saline. Furthermore, the mSG frequency increased with black widow spider venom extract and Ca^<2+> ionophore, A23187.
These results indicate that the remaining mSC's in n-syb mutants are Ca^<2+> dependent. In wild typ … More e larvae an elevation of cAMP in the presynaptic nerve terminal either by an activator of adenylate cyclase, forskolin, or by a membrane permeable analog of cAMP, db-cAMP, resulted in an increase in msc's. However, in n-syb mutants neither of these drugs increased the mSG frequency. Thus we conclude that the n-syb independent pathway for vesicle fusion is insensitive to cAMP (Yoshihara et at., 1999).
Cysteine-string protein (csp) is also vesicle protein and supposed to interact with voltage-gated Ca^<2+> channels in the terminal membrane. In a temperature sensitive mutant of csp no nerve-evoked synaptic currents were observed in non-permissive temperature (32 ゚C). This could be due to lack of function of voltage-gated Ca^<2+> channels at high temperature. To test this possibility we visualized terminal Ca^<2+> by a Ca^<2+> sensitive dye. At room temperature the Ca^<2+> concentration increase upon repetitive stimulation of nerve. However, at non-permissive temperature the Ca^<2+> signal decreased significantly, thus suggesting a failure of Ca^<2+> channel function.
Since csp is on the synaptic vesicle membrane it is possible that Ca^<2+> channels have to be associated with synaptic vesicles to operate properly. To test this.
possibility we used another mutant call shibire in which endocytosis is blocked at non-permissive temperature. We also found in shibire that Ca^<2+> signals were lower in non-permissive temperature. In conclusion, for voltage-gated Ca^<2+> channels in the presynaptic terminal to work properly vesicles might have to be docked to release sites (Umbach et al., 1998). Less

  • Research Products

    (21 results)

All Other

All Publications (21 results)

  • [Publications] Kuromi, H.& Kidokoro, Y.: "The optically determined size of exo/endo cycling vesicle pool correlates with the quantal content at the neuromuscular junction of Drosophila larvae" J.Neurosci.in press.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Zhang, D., Kuromi, H.& Kidokoro, Y.: "Synaptic transmission at the Drosophila neuromuscular junction ; Effects of metabotrophic glutamate receptor activation." Jpn.J.Physiol.in press.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Zhang, d., Kuromi, H.& Kidokoro, Y.: "Activation of metaboropic glutamate receptors enhances synaptic transmission at the Drosophila neuromuscular junction." Neuropharmcol.in press.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kuromi, H.& Kidokoro, Y.: "Two distinct pools of synaptic vesicles in single presynaptic boutons revealed in a temperature-sensitive Drosophila mutant." Neuron. 20. 917-925 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Saitoe, M., Koshimoto, H., & Kidokoro, Y.: "Distribution of functional glutamate receptors in cultured embryonic Drosophila myotubes revealed with focal release of L-glutamate from caged compound by." J.Neurosci.Meth.80. 163-170 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Umbach, U.A., Saitoe, M., Kidokoro, Y., et al.: "Attenuated influx of calcium ions at nerve endings of csp and shibire mutant Drosophila" J.Neurosci.18. 3233-3240 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Deitcher, D.L., Ueda, A., Kidokoro, Y.et al.: "Distinct requirements for evoked and spontaneous release of neurotransmitter are revealed by mutations in the Drosophila gene neuronal-synaptobrevin" J.Neurosci.18. 2028-2039 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kajiwara, R., Sand, O., Kidokoro, Y., et al.: "Functional organization of chromaffin cells and cholinergic synaptic transmission in rat adrenal medulla" Jpn.J.Physiol.47. 449-464 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yoshihara, M., Rheuben, M.B., & Kidokoro, Y.: "Transition from growth cone to functional motor nerve terminal in Drosophila embryos." J.Neurosci.17. 8408-8426 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Ciani, S., Nishikawa, K. & Kidokoro, Y.: "Permeation of organic cations and ammonium through the glutamate receptor channel in Drosophila larval muscle." Jpn.J.Physiol.47. 189-198 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Saitoe, M., Tanaka, S., Takata, K. & Kidokoro, Y.: "Neural activity affects distribution of glutamate receptors during neuromusculs junction formation in Drosophila embryos" Develop.Biol.184. 48-60 (1 97)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kuromi, H., Yoshihara, M. & Kidokoro, Y.: "An inhibitory role of calcineurin in endocytosis of synaptic vesicles at nerve terminals of Drosophila larvae" Neurosci.Res.27. 101-113 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Iino, M., Ciani, S., & Kidokoro, Y.: "Permeation properties of Na^+ and Ca^<2+> ions through the mouseξ/ζ_1 NMDA receptor channel expressed in Xenopus oocytes" J.Memb.Biol.155. 143-156 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Rheuben, M. B., Yoshihara, M.& Kidokoro, Y.: "Ultrastructural orrelates of neuromuscular junction development.in "Neuromuscular Junction in Drosophila"eds.Vivian Budnik et al." Landes Bioscience.(in press),

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Kuromi, H.& Kidokoro, Y.: "The optically determined size of exo/endo cycling vesicle pool correlates with the quantal content at the neuromuscular junction of Drosophila larvae" J.Neurosci.(in press).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Zhang, D., Kuromi, H.& Kidokoro, Y.: "Synaptic tranmsmission at the Drosophila neuromuscular junction ; Effects of metabotrophic glutamate receptor activation." Jpn.J.Physiol.(in press).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Zhang, D., Kuromi, H.& Kidokoro, Y.: "Activation of metaboropic glutamate receptors enhances synaptic transmission at the Drosophila neuromuscular junction." Neuropharmcol.(in press).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Kuromi, H.& Kidokoro, Y.: "Two distinct pools of synaptic vesicles in single presynaptic boutons revealed in a temperatue-sensitive Drosophila mutant" Neuron. 20. 917-925 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Saitoe, M., Koshimoto, H., ... & Kidokoro, Y.: "Distribution of functional glutamate receptors in cultured embryonic Drosophil myotubes revealed with focal release of L-glutamate from caged compound by ..." J.Neurosci.Meth.80. 163-170 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Umbach, U.A., Saitoe, M., Kidokoro, Y., et al.: "Attenuated influx of calcium ions at nerve endings of csp and shibire mutant Drosophila" J.Neurosci.18. 3233-3240 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Rheuben, M.B., Yoshihara, M.& Kidokoro, Y.: Landes Bioscience.(in press). Ultrastructural orrelates of neuromuscular junction develpment.in"Neuromuscular Junction in Drosophila"eds.Vivian Budnik et al.,

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

URL: 

Published: 1999-12-08  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi