| Project/Area Number |
17591947
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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 | Iwate Medical University |
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Principal Investigator |
KITADA Yasuyuki Iwate Medical University, Dental School, Professor, 歯学部, 教授 (80018423)
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| Co-Investigator(Kenkyū-buntansha) |
NARITA Kinya Iwate Medical University, Dental School, Lecturer, 歯学部, 講師 (40291083)
AKABANE Kazuhisa Iwate Medical University, Dental School, Assistant Professor, 歯学部, 助手 (70160801)
FUKAMI Hideyuki Iwate Medical University, Dental School, Assistant Professor, 歯学部, 助手 (30382625)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | taste reception / type of taste cell / membrane currents / intracellular Ca^<2+> / gustatory physiology / カエル / 味覚器 |
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| Research Abstract |
To investigate the mechanism of taste reception in taste cells, we used patch-clamp and Ca^<2+> imaging technique. In vertical slices of the bullfrog (Rana catesbeiana) taste disc, cell types were identified by staining with Alexa Fluor in a pipette. Calcium Green-1 Dextran (CaGD), a fluorescent Ca^<2+> indicator, was also added to the patch pipette. Lingual slices containing CaDG-labeled taste cells were imaged with a scanning confocal microscoe. Focal chemical stimulation was applied to the apical end of the taste disc. Focal bitter (quinine) stimulation induced an increase in membrane current and an increase in intracellular Ca^<2+> in type Ib and type II cells. In Ca^<2+> free bath solution, an increase in intracellular Ca^<2+> induced by bitter stimulation was observed in type Ib and type II cells. This suggests that focal bitter stimulation induce release of Ca^<2+> from internal stores. Focal Ca^<2+> (or Na^+) stimulation also induced an increase in membrane current and an increase in intracellular Ca^<2+> only in type III cells. Depolarization with high K^+ external solution induced an increase in intracellular Ca^<2+> only in type III cells. Therefore, an increase in intracellular Ca^<2+> in type III cells may be due to external Ca^<2+> via voltage- gated Ca^<2+> channels. The present results suggest that type Ib and type II cells are bitter-taste receptor cells and that type III cells are salt-taste receptor cells.
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