| Project/Area Number |
18592041
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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 | Kagoshima University |
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Principal Investigator |
HARADA Shuitsu Kagoshima University, Graduate School of Medical and Dental Sciences, Professor (60128452)
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| Co-Investigator(Kenkyū-buntansha) |
MIURA Hirohito Kagoshima University, Graduate School of Medical and Dental Sciences, Associate Professor (80353936)
NAKAYAMA Ayumi Kagoshima University, Graduate School of Medical and Dental Sciences, Assistant Professor (10398290)
TOMONARI Hiroshi Kagoshima University, Graduate School of Medical and Dental Sciences, Assistant Professor (70398288)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,540,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥240,000)
Fiscal Year 2007: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2006: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | soft palate / greater superficial petrosal nerve / chorda tvmpani nerve / taste bud / gustatory sensation / development / basal cell / mammal / マーカー分子 / マウス |
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| Research Abstract |
Gustducin was expressed in almost all (96.7%) IP3R3-expressing cells in taste buds of the soft palate (SP),whereas gustducin-positive cells were 42.4% and 60.1 % of IP3R3-expressing cells in the fungiform (FF) and circumvalate (CV) papillae, respectively. To confirm the broad role of gustducin in the taste transduction on the SP, responses from three major gustatory nerves in gustducin-KO mice were recorded electrophysiologically and the response properties were compared among the nerves. In consistent with the immunohistochemical results in the rat, nerve responses to both sweet and bitter stimuli were markedly reduced in the greater superficial petrosal nerve (GSP) of gustducin-KO mice. In contrast to the GSP, the chorda tympani nerve (CT) and the glossopharngeal nerve (GL) showed reduced responses to sweet and bitter stimuli, respectively. Immunohistochemistry of gustducin and IP3R3 in mice showed that 91.1% of IP3R3-expressing cells in the SP was gustducin positive. These results d
… More
emonstrate that gustducin is involved in the different lines of the taste-signaling pathway depending on the taste cell differentiation.
To examine the embryonic development of the basal cells, the expression of the basal cell markers of taste buds (Shh, Proxi and Mashi) was determined in the mouse embryo by in situ hybridization and immunohistochemistry. Proxi was co-expressed with Shh from the beginning of Shh expression in a punctate pattern on the anterior tongue (E1 2.5) and soft palatal region (E14.5),suggesting that the basal cells of taste buds and Shh-expressing spots in embryos share common features. Mashi expression lagged behind the expression of Shh and Proxi by approximately 2 days in both regions. Nerves reached the epithelium expressing Shh slightly before the onset of Mashi expression. These results suggest that the differentiation of the basal cells in the taste bud starts nerve-independently.
We analyzed regenerated taste buds induced by cross-regeneration of CT and GSP in rats and mice using immunohistochemistry and in situ hybridization. The results showed that the gustducin and IP3R3 co-expression between in the SP and FF after the regeneration with the different nerve supply were not depend on the nerve but on the epithelium. This result suggests that the same functional difference still remain after the cross-regeneration. Less
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