Temperature modulates taste responsiveness and stimulates gustatory neurons in the rat geniculate ganglion
Temperature modulates taste responsiveness and stimulates gustatory neurons in the rat geniculate ganglion
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DOI：
10.1152/jn.00793.2005
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发表时间：
2006-02-01
影响因子：
2.5
通讯作者：
Contreras, RJ
中科院分区：
文献类型：
--
作者：
Breza, JM;Curtis, KS;Contreras, RJ
温度调节味觉反应并刺激大鼠膝状神经节中的味觉神经元。 《神经生理学杂志》95：674-685，2006 年。首次发表于 2005 年 11 月 2 日； doi：10.1152/jn。 00793.2005。对于人类来说，温度会影响味觉强度和质量感知，而热刺激本身可能会引发味觉。然而，味觉的外围编码机制通常独立于温度的影响进行研究。在麻醉大鼠中，我们表征了在 10、25 和 40 摄氏度的稳定基线温度（适应）下膝状神经节神经元对 0.5 M 蔗糖、0.1 M 氯化钠、0.01 M 柠檬酸和 0.02 M 盐酸奎宁的单细胞反应；从适应的舌头温度 25 摄氏度逐渐冷却和升温（1 摄氏度/秒水温变化 > 5 秒）；从40℃的适应温度逐渐冷却；并从 10 摄氏度的适应温度逐渐变暖。对 25 摄氏度的味觉反应进行分层聚类分析，将 50 个神经元分为狭义调谐（蔗糖专家、氯化钠专家）和广义调谐（氯化钠通才 (I)、氯化钠通才 (II)、酸通才和 QHCl 通才）两大类。氯化钠专家对从 25 摄氏度冷却到 10 摄氏度感到兴奋，而从 10 到 25 摄氏度升温则抑制。酸性通才对从 40 到 25 摄氏度冷却感到兴奋，但从 25 到 10 摄氏度则不会。一般来说，随着适应温度的降低，广泛调节的神经元对所有刺激的味觉反应都会系统性地降低。蔗糖专家对蔗糖和氯化钠专家对氯化钠的响应选择性不受适应温度的影响。然而，蔗糖专家在 10 摄氏度下对蔗糖没有反应，而氯化钠专家在所有适应温度下对氯化钠的反应相同。总之，我们已经证明温度可以调节味觉反应，并且温度本身就是特定类型的外周味觉神经元激活的刺激。
Temperature modulates taste responsiveness and stimulates gustatory neurons in the rat geniculate ganglion. J Neurophysiol 95: 674-685, 2006. First published November 2, 2005; doi: 10.1152/jn. 00793.2005. In humans, temperature influences taste intensity and quality perception, and thermal stimulation itself may elicit taste sensations. However, peripheral coding mechanisms of taste have generally been examined independently of the influence of temperature. In anesthetized rats, we characterized the single-cell responses of geniculate ganglion neurons to 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, and 0.02 M quinine hydrochloride at a steady, baseline temperature (adapted) of 10, 25, and 40 degrees C; gradual cooling and warming (1 degrees C/s change in water temperature > 5 s) from an adapted tongue temperature of 25 degrees C; gradual cooling from an adapted temperature of 40 degrees C; and gradual warming from an adapted temperature of 10 degrees C. Hierarchical cluster analysis of the taste responses at 25 degrees C divided 50 neurons into two major categories of narrowly tuned (Sucrose-specialists, NaCl-specialists) and broadly tuned (NaCl-generalists(I), NaCl-generalists(II), Acid-generalists, and QHCl-generalists) groups. NaCl specialists were excited by cooling from 25 to 10 degrees C and inhibited by warming from 10 to 25 degrees C. Acid-generalists were excited by cooling from 40 to 25 degrees C but not from 25 to 10 degrees C. In general, the taste responses of broadly tuned neurons decreased systematically to all stimuli with decreasing adapted temperatures. The response selectivity of Sucrose-specialists for sucrose and NaCl-specialists for NaCl was unaffected by adapted temperature. However, Sucrose-specialists were unresponsive to sucrose at 10 degrees C, whereas NaCl-specialists responded equally to NaCl at all adapted temperatures. In conclusion, we have shown that temperature modulates taste responsiveness and is itself a stimulus for activation in specific types of peripheral gustatory neurons.