| Project/Area Number |
22300127
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 大阪大学, 歯学研究科(研究院), 教授 (50177755)
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| Co-Investigator(Kenkyū-buntansha) |
TOYODA Hiroki 大阪大学, 大学院歯学研究科, 准教授 (00432451)
SARO Hajjme 大阪大学, 大学院歯学研究科, 助教 (10432452)
SAITO Mitsuru 大阪大学, 大学院歯学研究科, 講師 (50347770)
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| Project Period (FY) |
2010-04-01 – 2013-03-31
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| Project Status |
Completed (Fiscal Year 2013)
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| Budget Amount *help |
¥18,460,000 (Direct Cost: ¥14,200,000、Indirect Cost: ¥4,260,000)
Fiscal Year 2012: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2011: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2010: ¥10,920,000 (Direct Cost: ¥8,400,000、Indirect Cost: ¥2,520,000)
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| Keywords | 三叉神経運動ニューロン / 漏洩Kチャネル / NO / 序列動員 / α運動ニューロン / γ運動ニューロン / 漏洩カリウムチャネル / サイズの原理 / 等尺性収縮 / 三叉神経 / 閉口筋 / 運動ニューロン / TASKチャネル / 一酸化窒素 / 入力抵抗 / 三叉神経運動核 / 等尺性筋収縮 |
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| Research Abstract |
The immunohistochemical analysis of motoneurons (MNs) in the trigeminal motor nucleus that innervates jaw-closing muscles revealed that TASK1 and TASK3 are complementary expressed in the soma and dendrites of MNs, respectively. The real-time RT PCR revealed that large MNs (>35 microm) expressed more TASK1/cell and TASK3 compared to small MNs (<20 microm). Consequently, larger MNs had smaller input resistance (IR) and more hyperpolarized resting membrane potentials (RMP) compared to smaller MNs. PKG activation enhanced TASK1 activity while it inhibited TASK3 activity. As the MN size becomes smaller, PKG activation more decreased the IR and hyperpolarized the RMP. The frequency distribution of sizes of alpha-MNs was found to display a bimodal distribution composed of smaller and larger alpha-MNs while gamma-MNs displayed a unimodal patter of smaller size. These finding provide crucial molecular and cellular bases of the rank-ordered recruitment of motor units in the jaw-closing movement.
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