Taste responses of neurons in the nucleus of the solitary tract of awake rats: an extended stimulus array.
Taste responses of neurons in the nucleus of the solitary tract of awake rats: an extended stimulus array.
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清醒大鼠孤束核神经元的味觉反应：扩展刺激阵列。
DOI：
10.1152/jn.1993.70.3.879
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发表时间：
1993
影响因子：
2.5
通讯作者：
Norgren,R
中科院分区：
文献类型：
--
作者：
Nakamura,K;Norgren,R
1.在孤束核(NST)内分离了57个味觉神经元，并用15种SAID化学物质进行了检测。平均而言，NST神经元对氯化钠、蔗糖、L-谷氨酸单钠、NaNO3和甘氨酸的反应良好(平均值=8.2~11.0峰/S)。对KCl、NH4Cl、HCl、苹果酸和奎宁(QHCl)的平均反应较低(平均=0.7-2.9)。对其他刺激(柠檬酸、氯化镁、果糖、麦芽糖和多聚糖)的平均反应介于这两个极端之间(平均值=4.3-5.1)。2.根据对四种标准刺激的最大反应，将神经元分类为：氯化钠最佳15个，蔗糖最佳23个，柠檬酸最佳17个，QHCl最佳2个。3.三种钠盐(平均值=15.7-20.8)对氯化钠效果最好的神经元反应强健且几乎相等，但对非钠盐(平均值=-0.1-4.6)的反应较弱且变化较大。蔗糖最好的神经元对蔗糖、甘氨酸和味精反应强烈(平均值=13.7-17.8)，但对其他糖(果糖和麦芽糖)和多糖(平均值分别为8.4、9.8和8.8)反应较弱。4.柠檬酸最佳神经元对柠檬酸和苹果酸的反应中等(平均值分别为9.4和4.7)，而对盐酸的反应较弱(平均值为3.1)。QHCl最佳的两个神经元对QHCl和MgCl2的反应中等(平均值分别为12.0和9.5)，而对其他刺激的反应较弱或根本不反应(平均值=-1.1~3.1)。5.与臂旁味觉神经元不同，延髓味觉细胞对含氯(-)的化学物质没有特异反应。对非钠盐的反应很弱且多变，通常发生在柠檬酸最好的神经元或QHCl最好的神经元中，而不是那些对钠盐反应强烈的神经元。在麻醉制剂中也观察到了类似的关系。6.对15个刺激下的57个神经元进行了系统聚类分析，得到了四个二级簇，它们主要由氯化钠最佳、蔗糖最佳、柠檬酸最佳和QHCl最佳四个神经元组成。尽管对神经元的分析只产生了四个这样的簇，但对15个刺激的类似分析分离了钠盐(氯化钠和NaNO3)、非钠盐(KCL、NH4Cl和MGCl2)、甜味剂(蔗糖、麦芽糖、果糖和甘氨酸)、酸(柠檬酸和苹果酸)和QHCl。7.谷氨酸单钠既能激活最好的氯化钠神经元，也能激活最好的蔗糖神经元，但刺激分析将其与钠盐结合在一起。
1. Fifty-seven taste neurons were isolated in the nucleus solitary tract (NST) and tested with 15 sapid chemicals. On average, NST neurons responded well to NaCl, sucrose, monosodium L-glutamate (MSG), NaNO3, and glycine (mean = 8.2-11.0 spikes/s). Mean responses to KCl, NH4Cl, HCl, malic acid, and quinine HCl (QHCl) were low (mean = 0.7-2.9). The average responses to the other stimuli (citric acid, MgCl2, fructose, maltose, and polycose) fell between these extremes (mean = 4.3-5.1). 2. On the basis of the largest response to the four standard stimuli, the neurons were classified as follows: 15 NaCl-best, 23 sucrose-best, 17 citric acid-best, and 2 QHCl-best. 3. The NaCl-best neurons responded robustly and nearly equally to the three sodium salts (mean = 15.7-20.8) but much less so and more variably to the nonsodium, chloride salts (mean = -0.1-4.6). Sucrose-best neurons responded strongly to sucrose, glycine, and MSG (mean = 13.7-17.8), but only moderately to the other sugars (fructose and maltose) and to polycose (mean = 8.4, 9.8, and 8.8, respectively). 4. Citric acid-best neurons responded moderately to citric and malic acid (mean = 9.4 and 4.7), but less so to HCl (mean = 3.1). The two QHCl-best neurons responded moderately to QHCl and MgCl2 (mean = 12.0 and 9.5), but weakly or not at all to the other stimuli (mean = -1.1-3.1). 5. Unlike parabrachial taste neurons, none of the medullary taste cells responded specifically to Cl(-)-containing chemicals. The responses that did occur to nonsodium salts were weak and variable and often occurred in either citric acid-best or QHCl-best neurons, rather than in those that responded vigorously to sodium salts. Similar relationships have been observed in anesthetized preparations. 6. A hierarchical cluster analysis for 57 neurons across 15 stimuli produced four second-order clusters that consisted primarily of NaCl-best, sucrose-best, citric acid-best, and QHCl-best neurons, respectively. Although the analysis for neurons produced only four such clusters, a similar analysis for the 15 stimuli separated the sodium salts (NaCl and NaNO3), nonsodium salts (KCL, NH4Cl, and MGCl2, sweeteners (sucrose, maltose, fructose, and glycine), acids (citric acid and malic acid), and QHCl. 7. Monosodium glutamate activated both NaCl-best and sucrose-best neurons, but the stimulus analysis clumped it with the sodium salts.(ABSTRACT TRUNCATED AT 400 WORDS)