Mechanism for specific synapse formation between taste cells and axons

味觉细胞和轴突之间特定突触形成的机制

• 批准号: 09470407
• 负责人: NINOMIYA Yuzo
• 金额: $ 6.02万
• 依托单位: Asahi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09470407/
• 关键词: synapse formation; taste cells and axons; cross regeneration; congenic mice; gurmarin; sweet tasting gene; 味覚受容体; dpa遺伝子; コンジェニック系; 遺伝子導入; マイクロサテライト; 鼓索神経; 舌咽神経

Mechanisms responsible for synaptic connection between sweet-sensitive taste cells and nerve fibers were studied by examining responses of single nerve fibers to sweet substances and their inhibition by gurmarin, a specific inhibitor for sweet responses, in C57BL mice. Sweet responses of the chorda tympani (CT) nerve were inhibited by gurmarin, whereas no such inhibition was observed in those of the glossopharyngeal nerve, suggesting that taste cells located on the anterior tongue region possess gurmarin-sensitivity but those on the posterior region lack the sensitivity. CT nerve fibers predominantly responsive to sucrose (sucrose-best fibers) were divided into two groups, one is sensitive to gurmarin (GS-type) and the other insensitive to it (GI-type). This suggests specific synaptic connection between gurmarin-sensitive or insensitive taste cells and GS or GI-type taste axons. Nextly, we made congenic strain whose dpa locus controling gurmarin-sensitivity was donated form C57BL but other genetic backgrounds were same as those of BALB lacking gurmarin-sensitivity, and found that the congenic strain exhibits gurmarin-sensitivity, and possess GS-type CT fibers. This indicates that genetic induction of gurmarin-sensitivity in the congenic mouse taste cells is accompanied by co-existence of the GS-type fibers. Finally, we examined gurmarin-sensitivity of cross-regenerated CT and glossopharyngeal fibers. Although so far we have obtained little amount of data to make any conclusion, for the time being the obtained results may support the idea that cross regenerated GS-type axons may selectively reinnervate gurmain-sensitive taste cells.

通过检查单神经纤维对甜味物质的反应及其对C57BL小鼠中甜味反应的特定抑制剂的抑制作用，研究了可导致甜敏感细胞和神经纤维之间突触连接的机制。 gurmarin抑制了鼓膜（CT）神经的甜味反应，而在舌咽神经的神经中没有观察到这种抑制作用，这表明位于前舌区域上的味道细胞具有Gurmarin-敏感性，但在侧面区域缺乏敏感性。 CT神经纤维主要响应于蔗糖（蔗糖最好的纤维）分为两组，一组对Gurmarin（GS-Type）敏感，另一组对其敏感（GS-Type）（Gi-type）。这表明Gurmarin敏感或不敏感的味觉细胞与GS或Gi-Type味觉轴突之间的特定突触连接。几乎，我们制造了先天性菌株，其DPA基因座控制Gurmarin-敏感性是C57BL形式的，但其他遗传背景与缺乏Gurmarin敏感性的BALB相同，并发现相似的菌株表现出Gurmarin敏感性，并且具有GS-type ct fibers。这表明，gurmarin-敏感性在优质小鼠味道细胞中的遗传诱导伴随着GS型纤维的共存。最后，我们检查了跨再生CT和舌咽纤维的Gurmarin-敏感性。尽管到目前为止，我们几乎没有得到任何数据来得出任何结论，但目前，获得的结果可能支持交叉再生的GS型轴突可以选择性地加剧Gurmain对Gurmain敏感的味觉细胞的想法。

项目成果

Hellekant,G: "Taste in chimpangees III:Labeled-line coding in sweet taste" Physiology and Behavior. (印刷中). (1998)

Hellekant，G：“黑猩猩的味觉 III：甜味中的标记线编码”《生理学与行为》（出版中）。

Ninomiya,Y.et al.: "Reduction of the suppressive effects of gurmarin on sweet taste responses by addition of β-cyclodextrin." Chem.Senses. 23. 303-307 (1998)

Ninomiya, Y. 等人：“通过添加 β-环糊精减少古马林对甜味反应的抑制作用。”Chem.Senses 23. 303-307 (1998)

Ninomiya.Y.: "Sweet taste responses of mouse chorda tympani neurons : Existence of gurmarin-sensitive and -insensitive receptor components"J. Neurophysiol.. 81. 3087-3091 (1999)

Ninomiya.Y.：“小鼠鼓索神经元的甜味反应：古尔马林敏感和不敏感受体成分的存在”J。

Ninomiya,Y.: "Reinnervation of cross-regenerated gustatory nerve fibers into amiloride-sensitive and amiloride-insensitive taste receptor cells." Proc.Natl.Acad.Sci.USA. 95. 5347-5350 (1998)

Ninomiya，Y.：“将交叉再生的味觉神经纤维重新神经支配到阿米洛利敏感和阿米洛利不敏感的味觉受体细胞。”

Ninomiya.Y.: "Lack of gurmarin sensitivity of sweet taste receptors innervated by the glossopharyngeal nerve in C57BL mice"Am. J. Physiol.. 272. R1002-R1006 (1997)

Ninomiya.Y.：“C57BL 小鼠舌咽神经支配的甜味受体缺乏古尔马林敏感性”Am。