| Project/Area Number |
03304026
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurophysiology and muscle physiology
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| Research Institution | Gunma University |
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Principal Investigator |
OZAWA Seiji Gunma University, School of Medicine, Professor, 医学部, 教授 (40049044)
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| Co-Investigator(Kenkyū-buntansha) |
HIGASHI Hideho Kurume University, School of Medicine, Associate Professor, 医学部, 助教授 (10098907)
TAKAHASHI Tomoyuki Tokyo University, School of Medicine, Professor, 医学部, 教授 (40092415)
AKAIKE Noriko Kyusyu University, School of Medicine, Professor, 医学部, 教授 (30040182)
ONODERA Kayoko Tokyo University, School of Medicine, Lecture, 医学部, 講師 (00053091)
MISHINA Masayoshi Niigata University, Institute of Brain Research, Professor, 脳研究所, 教授 (80144351)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Synapse / Glutamate receptor / NMDA / AMPA / Intracellular calcium / Transmitter release / cDNA cloning / Plastic change |
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| Research Abstract |
In this study, we investigated molecular and cellular basis of synaptic transmission in the three aspects, namely 1)molecular structure and electrophysiological properties of receptor channels, 2)regulation of calcium metabolism and its relation to transmitter release, and 3)mechanism of synaptic plasticity. The main results are as follows.
1.Molecular structure and functional properties of receptor channels
Mishina has identified four modulatory subunits (epsilon1-epsilon4)of the mouse NMDA receptor by cloning and expression of cDNAs. This molecular diversity of the epsilon subunits underlies the functional heterogeneityb of the NMDA receptor. Ozawa has coupled patch-clamp recordings and reverse transcription followed by PCR amplification, and identified the subunit composition of the Ca^<2+>-permeable AMPA receptor at the single cell level. Takahashi has expressed fetal- and adult-type glycine receptor cDNAs, and shown that the mean open time of the adult-type receptor has a shorter op
… More
en time. This result is consistent with that the decay time of glycinergic IPSCs becomes shorter during postnatal development.
2.Calcium metabolism and transmitter release
Kuba has measured intracellular Ca^<2+> concentration in sympathetic neurons and presented the evidence that the activation of calcium-induced calcium release occurs as a result of Ca^<2+>-influx through voltage-dependent Ca^<2+> channels. Yawo has shown that Ca^<2+>-influx through the N-type Ca^<2+> channel mediates transmitter release from the chick ciliary presynaptic terminal. Tachibana has demontrated that the transmitter of the ganglion cell of the goldfish retina is L-gluatamate, and that this transmitter release is mediated by the activation of L-type Ca^<2+> channels.
3.Mechanism of synaptic plasticity
Hirano has investigated the mechanism of long-term depression (LTD) of the synaptic transmission between cerebellar granule and Purkinje cells, presenting the evidence that the adtivation of metabotropic glutamate receptor (mGluR1) is involved in the induction of LTD. Less
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