1992 Fiscal Year Final Research Report Summary
Excitation and inhibition in trigeminal motoneurons by palatal stimulation
| Project/Area Number |
03454432
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Functional basic dentistry
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| Research Institution | The University of Tokushima |
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Principal Investigator |
TAKATA Mitsuru Tokushima University, School of Dentistry, Professor, 歯学部, 教授 (40028725)
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| Co-Investigator(Kenkyū-buntansha) |
TOMIOKA Shigemasa Tokushima University, School of Dentistry, University Dental Hospital, Research, 歯学部・附属病院, 助手 (70188770)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Trigeminal motoneurons / Postsynaptic potentials / Palatal stimulation / Jaw movements |
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| Research Abstract |
Excitation and inhibition of jaw-closer (Masseteric and Temporal Motoneurons, Mass. and Temp.Mns) and jaw-opener (Digastric Motoneurons, Dig. Mns) motoneurons during transient jaw closing, the so-called jaw-closing reflex, and prolonged jaw opening elicited by palatal stimulation were studied in cats. By pressing the anterior palatal surfaces sustained jaw opening was elicited, suggesting that sustained jaw opening results from inhibition of tonic background activity of jaw-closer motoneurons by IPSPs elicited by mechanical stimulation of the palate. With respect to Dig. Mns, an increase of firing frequency of Dig. Mns occurred 40ms before the onset of jaw opening and continued for 80ms. In addition, application of diffuse pressure stimulation to the posterior palatal surface produced the jaw-closing reflex, and it was found that mechanosensory inputs from the posterior palatal mucosa produce depolarizingpotentials on the Temp. and Mass. Mns responsible for jaw closure during the jaw-closing reflex. Furthermore, it was found that mechanosensory inputs from the posterior palatal mucosa produce a hyperpolarization-depolarization sequence in the Dig. Mns responsible for the jaw-closing reflex.
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