Coding of gustatory information in the NTS from the soft palate.

在哺乳动物中，岩浅大神经支配软腭上的味蕾并投射至孤束核。来自大鼠GSP的电生理记录显示，GSP对甜味物质产生强烈的反应。大鼠行为学实验表明，切断GSP和/或鼓索（CT）可显著减少蔗糖溶液的摄入量。然而，GSP仅在大鼠中进行了研究，并且仍然不清楚。本实验从神经生理学和行为学两个方面研究了GSP的功能。神经记录显示，仓鼠GSP也对各种糖产生强烈的反应。在大鼠中，GSP表现出相当的敏感性，蔗糖，而CT是更敏感的NaCl。GSP对阿米洛利几乎不敏感，而CT对Na^+的反应则被阿米洛利抑制。本实验采用条件性味觉厌恶实验范式，研究了双侧切断GSP和/或CT对辨别蔗糖味的影响。厌恶的程度显着下降时，。对GSP和/或CT进行双侧切片。切片效果的顺序为GSP+CT>GSP>= CT>sham。这些结果表明，味觉信息通过GSP粘贴到NTS是重要的甜物质的歧视和编码机制的NTS。在NTS中进行更多的实验以阐明考虑GSP功能的味觉编码机制是必要的。

The greater superficial petrosal(GSP)nerve innervates taste buds on the soft palate and project to nucleus tractus solitarius(NTS)in mammals. Electrophysiological recordings from the rat's GSP revealed that the GSP produces robust responses to sweet substances. Behavioral experiment in the rat showed that sectioning of the GSP and/or the chorda tympani(CT)resulted in significant decrease of sucrose solution intake. However, the GSP is only investigated in the rat and is still remained unclear. In this experiment, functions of the GSP were studied in the hamster and the rat neurophysiologically and behaviorally. Neural recordings revealed that the hamster GSP also produces robust responses to various sugars. In the rat, the GSP showed considerably sensitivity to sucrose while the CT was more sensitive to NaCl. And the GSP showed almost no sensitivity to amiloride while response to Na^+ in the CT was depressed by amiloride. Effects of bilateral sectionings of the GSP and/or CT on discriminating sucrose taste were examined through conditioned taste aversion paradigm in the hamster. The degree of the aversion was significantly decreased when the. GSP and/or CT were sectioned bilaterally. The order of the sectioning effects were GSP+CT>GSP>= CT>sham. These results suggest that gustatory information pasted through the GSP to the NTS is important for the discrimination of sweet substances and for the coding mechanisms in the NTS. More experiments in the NTS are necessary to clarify the gustatory coding mechanisms considering the GSP function.