| Project/Area Number |
12640666
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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 |
動物生理・代謝
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
YOSHII Kiyonori Kyushu Institute of Technology, Graduate School of Life Science and Systems Engineering, Professor, 大学院・生命体工学研究科, 教授 (30125364)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | taste / voltage-clamp / Optical recordings / voltage-sensitive dye / action potentials / receptor potentials / chemical synapses / neurotransmitter / 味蕾 / 味細胞 / 光学的測定 / 脱分極 / 過分極 |
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| Research Abstract |
Single-taste buds in mouse fungiform papillae consist of 〜50 elongated cells (TBCs), where fewer than three TBCs have synaptic contacts with taste nerves. We investigated whether the non-innervated TBCs were chemosensitive with a voltage-sensitive dye, tetramethylrhodamine methyl ester (TMRM) under an in situ optical recording condition. Before optical recordings, we investigated the magnitude and polarity of receptor potentials under in-situ whole-cell clamping conditions. In response to 10 mM HCl, several TBCs were depolarized by 〜25 mV and elicited action potentials, while different TBCs were hyperpolarized by 12 mV. The TBCs eliciting hyperpolarizing receptor potentials also generated action potentials on electrical stimulation. The mixture of 100 mM NaCl, 10 mM HCl, and 500 mM sucrose depolarized six TBCs and hyperpolarized another three TBCs out of 13 identified TBCs in a taste bud viewed by optical section. At an optical section of another taste bud, 1M NaCl depolarized five TBCs and hyperpolarized another two TBCs out of identified 11 TBCs. The number of chemosensitive TBCs was much larger than that of innervated TBCs in a taste bud, showing chemosensitivity in non-innervated TBCs. There was a tendency that TBCs eliciting the same polarity of receptor potential occurred together in taste buds. We discuss the role of non-innervated TBCs in taste information processing.
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