Budget Amount *help |
¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2012: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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Outline of Final Research Achievements |
The mastication of foods occurs during the slow-closing phase of the mastication cycle, in which isometric contraction of jaw-closing muscles is developed through the rank-ordered recruitment of jaw-closing motoneurons (MNs). However, its molecular mechanism remains unknown. Here we show that TWIK-related acid-sensitive K+ channel-1 (TASK1) and TASK3 channels, which determine the input resistance and resting membrane potential, are differentially expressed between small and large MNs and play critical roles in the rank-ordered recruitment of jaw-closing MNs. The principle of the rank-ordered recruitment was originally proposed based on the conduction velocity of the motor nerve fibers innervating a set of muscle fibers. After a half-century, we for the first time disclosed the molecular mechanism for the rank-ordered recruitment of jaw-closing MNs.
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