2007 Fiscal Year Final Research Report Summary
Modulation of excetability in primary sensory neurons
| Project/Area Number |
18500310
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurophysiology and muscle physiology
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| Research Institution | Osaka University |
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Principal Investigator |
KANG Youngnam Osaka University, Graduate School of Dentistry, Professor (50177755)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Mitsuru Osaka University, Graduate School of Dentistry, Research Associate (50347770)
SATO Hajime Osaka University, Graduate School of Dentistry, Research Associate (10432452)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Persistent Na^+ current / Initiation of action notential / Mesenceohalic triaeminal nucleus / Riluzole / Tetrodotoxin / OX-314 / Axon initial seanent / Spike backpropagation |
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| Research Abstract |
It has recently been shown that the persistent Na^+ current (l_NaP) is generated in the proximal axon in response to somatic depolarization in neocortical pyramidal neurons, while the involvement of l_NaP in spike-initiation is still unclear. Here we show a potential role of l_NaP in spike-initiation of primary sensory neurons in the mesencephalic trigeminal nucleus (MTN) that display a backpropagation of the spike initiated in the stem axon toward the soma in response to soma depolarization. Riluzole (10 μM) and tetrodotoxin (10 nM) caused an activation delay or a stepwise increase in the threshold for evoking soma spikes (S-spikes) without affecting the spike itself. Simultaneous patch-clamp recordings from the soma and axon hillock (AH) revealed that bath application of 50 nM tetrodotoxin increased the delay in spike activation in response to soma depolarization, leaving the spike-backpropagation time from the AH to soma unchanged. This indicates that the increase in activation delay occurred in the stem axon. Furthermore, under a decreasing intracellular concentration gradient of QX-314 from the soma to AH created by QX-314-containing and QX-314-free patch pipettes, the amplitude and maximum rate of rise (MRR) of AH-spikes decreased with an increase in the activation delay following repetition of current pulse injections, while S-spikes displayed much less decreases in amplitude and MRR. This suggests that comparing to S-spikes, AH-spikes more accurately reflect the attenuation of axonal-spike by QX-314, consistent with the spike-backpropagation nature. These observations strongly suggest that low-voltage-activated I_NaP is involved in spike-initiation in the stem axon of MTN neurons.
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[Journal Article] Differential columnar processing in local circuits of barrel and insular cortices2008
Author(s)
Sato, H., Shimanuki, Y., Saito, M., Toyoda, H., Nokubi, T., Maeda, Y., Yamamoto, T., Kang, Y
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Journal Title
The Journal of Neuroscience 28
Pages: 3076-3089
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] cGMP activates a pH-sensitive leak K' current in the presumed cholinergic neuron of basal forebrain2008
Author(s)
Toyoda, H., Saito, M., Sato, H., Dempo, Y., Ohashi, A., Hirai, T., Maeda, Y., Kaneko, T., Kang, Y
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Journal Title
ournal of Neuroplrysiology 99
Pages: 2126-2133
Description
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[Journal Article] Nitric oxide activates leak K^+ currents in the presumed cholinergic neuron of basal forebrain2007
Author(s)
Kang, Y., Dempo, Y., Ohashi, A., Saito, M., Toyoda, H., Sato, H., Koshino, H., Maeda, Y., Hirai, T
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Journal Title
Journal of Neurophysiology 98
Pages: 3397-3410
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Involvement of persistent Na' current in spike initiation in primary sensory neurons of the rat mesencephalic trigeminal nucleus2007
Author(s)
Kang, Y., Saito, M., Sato, H., Toyoda, H., Maeda, Y., Hirai, T., Bae, Y.C
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Journal Title
Journal of Neurophysiology 97
Pages: 2385-2393
Description
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[Journal Article] Two opposing roles of 4-AP-sensitive K current in initiation and invasion of spikes in rat mesencephalic trigeminal neurons2006
Author(s)
Saito, M., Murai, Y., Sato, H., Bae, Y.C., Akaike, T., Takada, M., Kang, I
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Journal Title
Journal of Neurophysiology 96
Pages: 1887-1901
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Functional roles of 5-HT_3/4 receptors in neurons of rat dorsal motor nucleus of the vagus2006
Author(s)
Fukushi, E., Saito, M., Sato, H., Endo, T, Hamaue, N., Hirafuji, M., Minami, M., Kang, Y
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Journal Title
Neuroscience 141
Pages: 675-685
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Phospholipase C-related catalytically inactive protein (PRIP) regulates GABAA responses in the barrel cortex2007
Author(s)
Hirao, K., Ogawa, T., Toyoda, IL, Saito, M., Sato, H., Kanematsu, T., Hirata, M., Kang, Y
Organizer
Society for Neuroscience 37th Annual Meeting
Place of Presentation
an Diego Convention Center, San Diego, CA, USA
Year and Date
2007-11-05
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Nitric oxide activates TASKI-like leak K channels in the presumed cholinergic neuron of basal forebrain2007
Author(s)
Toyoda, H., Saito, M., Sato, H., Dempo, Y., Ohashi, A, Hirai, T., Maeda, Y, Kaneko, T., Kang, Y
Organizer
Society for Neuroscience 37th Annual Meeting
Place of Presentation
San Diego Convention Center, San Diego, CA, USA
Year and Date
2007-11-04
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Differential involvement of GABAA IPSPs in intercolumnar communication in the barrel and insular cortices2006
Author(s)
Kang, Y., Shimanuki, Y., Saito, M., Sato, H., Toyoda, H
Organizer
Society for Neuroscience 36th Annual Meeting
Place of Presentation
Georgia World Congress Center, Atlanta, GA, USA
Year and Date
2006-10-16
Description
「研究成果報告書概要(欧文)」より
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