Morphological and Electrophysiological Studies on the Formation of the Neural Tract and the Function in the Taste of Frog Chimerae.

青蛙嵌合体神经束形成及其味觉功能的形态学和电生理学研究。

基本信息

批准号：
63540579
负责人：
YAMASHITA Satoru
金额：
$ 0.83万
依托单位：
Kagoshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63540579/
关键词：
Taste African Clawed Toad Gustatory Center Glossopharyngeal nerve Xenopus Feeding Behavior Taste Receptor Chimera

项目摘要

1. Of various agar-soaked gustatory stimuli, Xenopus (X. borealis and X. laevis) accepted L-Pro, L-Trp, and L-Val, while rejected L-Arg, quinine, and HCl. In general, X. borealis was more active and had lower thresholds for these gustatory stimuli than X. laevis. Feeding behavior of chimerae, which were produced by joining a half of an embryo of one species with that of another species, revealed similar behavior to X. laevis, regardless of the location of a half of an embryo of X. borealis.2. Taste buds calculated by staining with Ponceau S were about 300 on the palate, and about 200 on the floor of the mouth, and densely distributed on the inner lip and around the internal nostril. Both the number and location of the taste bud were similar among the two species and chimera. It was confirmed by staining with quinacrine that taste cells originated from an embryo of X. borealis are located ipsilaterally in chimerae. The extent of their contralateral location, however, were left unclear. Morphological tracing of glossopharyngeal nerves with HRP techniques showed that central gustatory neurons are distributed ipsilaterally in the medulla oblongata.3. Major differences in gustatory responses of the glossopharyngeal nerves to 60 gustatory stimuli between the two species were as follow: (1) L-Phe caused significant differences in responses over all concentrations tested, whereas L- and D-Trp, and L- and D-Tyr produced prominent differences in responses within a given concentration range. (2) differences in responses to quinine and strychnine were demonstrated throughout a wide concentration range. (3) among various nucleotides and nucleosides only adenosine produced fairly large responses in X. borealis, but very small responses in X. laevis. It was demonstrated using these substances as key stimuli that glossopharyngeal nerves of chimerae cause species-specific responsiveness during young adult, but that they tend to produce the responsiveness of X. laevis with aging.

1. 在各种琼脂浸泡的味觉刺激中，非洲爪蟾（X. borealis 和 X. laevis）接受 L-Pro、L-Trp 和 L-Val，而拒绝 L-Arg、奎宁和 HCl。一般来说，与非洲角鲨相比，北极角线虫更活跃，并且对这些味觉刺激的阈值更低。嵌合体的摄食行为是通过将一个物种的一半胚胎与另一物种的胚胎连接而产生的，显示出与 X. laevis 相似的行为，无论 X. borealis 的一半胚胎的位置如何。2。通过丽春红S染色计算味蕾，上颚约300个，口底约200个，密集分布在内唇和内鼻孔周围。这两个物种和嵌合体的味蕾数量和位置相似。通过奎纳克林染色证实源自X.borealis胚胎的味觉细胞位于嵌合体的同侧。然而，它们对侧位置的范围尚不清楚。 HRP技术对舌咽神经的形态学追踪显示，中枢味觉神经元分布于延髓同侧。 3．两个物种舌咽神经对60种味觉刺激的味觉反应的主要差异如下：（1）L-Phe在所有测试浓度下引起显着反应，而L-和D-Trp、L-和D -Tyr 在给定浓度范围内产生显着的响应差异。 (2) 在很宽的浓度范围内，对奎宁和士的宁的反应存在差异。 (3)在各种核苷酸和核苷中，只有腺苷在X.borealis中产生相当大的反应，但在X.laevis中产生很小的反应。研究表明，使用这些物质作为关键刺激物，嵌合体的舌咽神经在年轻时会引起物种特异性的反应，但随着年龄的增长，它们往往会产生非洲虎的反应。