Taste responses of neurons of the hamster solitary nucleus are enhanced by lateral hypothalamic stimulation
Taste responses of neurons of the hamster solitary nucleus are enhanced by lateral hypothalamic stimulation
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DOI：
10.1152/jn.00765.2001
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发表时间：
2002-04-01
影响因子：
2.5
通讯作者：
Smith, DV
中科院分区：
文献类型：
--
作者：
Cho, YK;Li, CS;Smith, DV
脑干的味觉反应可以被几种生理因素改变，包括血液中的胰岛素和葡萄糖、十二指肠内脂肪、胃扩张和学习，尽管这些调节作用的神经底物尚不清楚。刺激下丘脑的外侧会增加食物的摄入量和味觉偏好行为的改变，而对这一区域的损害则会产生相反的效果。在本研究中，我们观察了刺激黄体生成素对金黄地鼠孤束核味觉反应细胞神经活动的影响。将双极刺激电极植入双侧LH区，测试NST内99个神经元对同侧和对侧LH区刺激的反应，这些神经元首次以味觉敏感性为特征。NST中有一半的味觉反应细胞(49/99)受到刺激LH值的调节。对侧刺激(41个细胞)比同侧(13个细胞)更有效，而且总是兴奋的；10个细胞是双侧兴奋的。6个细胞受到同侧刺激的抑制。将谷氨酸受体激动剂同型半胱氨酸(DLH)微量注射到LH区，观察其中一组细胞(n=13)的作用。电刺激的效应完全被DLH所模拟，这表明这些效应是由LH区及其周围的细胞体负责的。电刺激促黄体生成素对0.032 M蔗糖、氯化钠、奎宁盐酸盐和0.0032 M柠檬酸刺激舌的反应的影响。由于黄体生成素的兴奋性影响，对味觉刺激的反应增加了一倍以上。这些数据表明，黄体生成素除了在摄食和新陈代谢中发挥作用外，还通过脑干对味觉信息的处理施加下行控制。
Gustatory responses in the brain stem are modifiable by several physiological factors, including blood insulin and glucose, intraduodenal lipids, gastric distension, and learning, although the neural substrates for these modulatory effects are not known. Stimulation of the lateral hypothalamus (LH) produces increases in food intake and alterations in taste preference behavior, whereas damage to this area has opposite effects. In the present study, we investigated the effects of LH stimulation on the neural activity of taste-responsive cells in the nucleus of the solitary tract (NST) of the hamster. Bipolar stimulating electrodes were bilaterally implanted in the LH, and the responses of 99 neurons in the NST, which were first characterized for their taste sensitivities, were tested for their response to both ipsilateral and contralateral LH stimulation. Half of the taste-responsive cells in the NST (49/99) were modulated by LH stimulation. Contralateral stimulation was more often effective (41 cells) than ipsilateral (13 cells) and always excitatory; 10 cells were excited bilaterally. Six cells were inhibited by ipsilateral stimulation. A subset of these cells (n = 13) was examined for the effects of microinjection of DL-homocysteic acid (DLH), a glutamate receptor agonist, into the LH. The effects of electrical stimulation were completely mimicked by DLH, indicating that cell somata in and around the LH are responsible for these effects. Other cells (n = 14) were tested for the effects of electrical stimulation of the LH on the responses to stimulation of the tongue with 0.032 M sucrose, NaCl, and quinine hydrochloride, and 0.0032 M citric acid. Responses to taste stimuli were more than doubled by the excitatory influence of the LH. These data show that the LH, in addition to its role in feeding and metabolism, exerts descending control over the processing of gustatory information through the brain stem.