2012 Fiscal Year Final Research Report
Elucidation of control mechanisms of oral, facial, tongue sensation and jaw, facial, head movements during mastication
| Project/Area Number |
22592079
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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 |
Functional basic dentistry
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| Research Institution | The Nippon Dental University |
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Principal Investigator |
SATOH Yoshihide 日本歯科大学, 新潟生命歯学部, 准教授 (20287775)
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| Project Period (FY) |
2010 – 2012
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| Keywords | 口腔・顔面・舌感覚 / 顎・顔面・頭部運動 / 咀嚼 |
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| Research Abstract |
This study first examines whether stimulation of the vestibular nuclear (VN) complex can modulate rhythmic jaw movements and the rhythmic activity of the neck muscles. Rhythmic jaw movements were induced by repetitive electrical stimulation of the orofacial motor cortex. An electromyogram in the splenius muscles (spEMG) showed rhythmic bursts during the jaw-opening phase or during the transition from the jaw opening phase to the jaw-closing phase. In the sternomastoid (stEMG), however, the electromyogram did not show any bursts during rhythmic jaw movements. Stimulation of the medial vestibular nucleus (MVN) during the jaw-closing phase increased the amplitude of the jaw-closing movement, induced a transient burst in the stEMG, and the duration of activity in the spEMG was increased. Stimulation of the MVN during the jaw-opening phase disturbed the rhythm of jaw movements, induced a small jaw-closing movement, a transient burst in the stEMG and an inhibitory period in the spEMG. Stimulation of the superior and the lateral VN during the jaw-opening phase increased the amplitude of the jaw opening movement. Stimulation of the inferior VN during the jaw-closing and the jaw-opening phase respectively decreased the amplitude of the jaw-closing and the jaw-opening movements. These results imply that the VN is involved in the modulation of rhythmic jawmovements and neck muscle activities. A further study then examines the neuronal activities of the VN neurons during rhythmic jaw movements. Rhythmic jaw movements were induced by mechanical stimulation of the palate mucosa. The firing rate of approximately 25% of VN neurons increased significantly, and that of 10% of VN neurons decreased significantly, during these rhythmic jaw movements. There was no correlation between the change in the firing rate and the phase of the rhythmic jaw movements (jaw-opening and jaw-closing phases). These results suggest that the VN neurons areinvolved in controlling jaw movements.
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Research Products
(14 results)
