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。

• 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

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，非洲爪哇(X.borealis和X.laevis)接受L-Pro、L-Trp和L-Val，拒绝L-Arg、奎宁和盐酸。总体而言，北极按蚊对这些味觉刺激的反应更活跃，阈值也比莱氏按蚊低。嵌合体的取食行为是通过将一个物种的一半胚胎与另一个物种的胚胎连接而产生的，表现出与莱维氏X.laevis相似的行为，而不考虑X.borealis的一半胚胎的位置。用丽水S染色计算，味蕾在腭部约300个，口底约200个，密集分布在内唇和内鼻孔周围。两种和嵌合体的味蕾在数量和位置上都相似。喹卡林染色证实，来源于北方按蚊胚胎的味觉细胞位于嵌合体的同侧。然而，他们对侧位置的范围尚不清楚。用HRP技术对舌咽神经进行形态追踪，发现中央味觉神经元分布于同侧延髓。两种动物舌咽神经对60种味觉刺激的味觉反应的主要差异如下：(1)L-苯丙氨酸在所有浓度范围内引起显著差异，而L和D-色氨酸、L和D-酪氨酸在一定浓度范围内引起显著差异。(2)在较宽的浓度范围内，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，只有腺苷对北极血吸虫的反应较大，而对莱氏血吸虫的反应很小。研究表明，以这些物质为关键刺激，嵌合体的舌咽神经在幼虫时期引起种属特异性反应，但随着年龄的增长，它们往往产生莱氏X.laevis的反应。

项目成果

山下智,郡山博司,大平博之,清原貞夫: "アフリカツメガエル2種とそのキメラにみられる味覚神経応答の特異性" Jpn.Symp.Taste and Smell. 23. 115-118 (1989)

Satoshi Yamashita、Hiroshi Koriyama、Hiroyuki Ohira、Sadao Kiyohara：“在两种爪蟾及其嵌合体中观察到的味觉神经反应的特异性”Jpn.Symp.Taste and Smell 23. 115-118 (1989)。

Satoru Yamashita: "Chemospecificities of gustatory responses of two species of Xenopus and the chimera." Jpn. Symp. Taste and Smell. 23. 115-118 (1989)

Satoru Yamashita：“两种爪蟾和嵌合体的味觉反应的化学特异性。”