Forebrain Activation by Postoral Nutritive Substances
Forebrain Activation by Postoral Nutritive Substances
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经口营养物质激活前脑
DOI：
--
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
K. Torii
中科院分区：
文献类型：
--
作者：
T. Kondoh;K. Torii
L-谷氨酸是一种多功能氨基酸，参与鲜味的感知、中间代谢和兴奋性神经传递。最近的研究揭示了饮食谷氨酸在肠-脑轴激活和能量稳态中的新作用。谷氨酸受体及其细胞转导分子最近已在肠上皮细胞中被鉴定。刺激肠道谷氨酸受体可增强谷氨酸转运蛋白的顶端表达，并触发信号分子如一氧化氮和血清素的释放。这些信号分子的释放激活迷走神经传入神经纤维，并因此激活迷走神经输入直接或间接靶向的不同脑区域。更一般地说，证据积累支持的概念，一个特定的大脑系统，特别是响应迷走神经激活，参与感知饮食谷氨酸产生的摄食后效应。值得注意的是，大脑的三个区域，内侧视前区，下丘脑背内侧核和缰核被谷氨酸的胃内输注激活，但不被葡萄糖或NaCl输注激活。这些谷氨酸特异性的脑反应似乎依赖于迷走神经的传输，因为完全横断的subjummatic迷走神经干废除谷氨酸（MSG）诱导的脑激活，但不是由胃内葡萄糖输注诱导的。相反，腹侧被盖区多巴胺能神经元的损伤会降低对蔗糖的行为偏好，但不会降低对鲜味溶液（味精和5′-核糖核苷酸）的偏好。与这些研究结果一致，胃迷走神经切断术专门减少味精的总摄入量，并在60 mM的味精，但不是葡萄糖或NaCl的胃内输注;它还诱导大鼠的口味偏好学习。最后，谷氨酸的消耗对新陈代谢和体重产生营养特异性影响。事实上，大鼠长期随意摄入1%（w/v）味精的可口溶液与摄入普通水相比，可减少体重增加、脂肪沉积和血浆瘦素水平。这种效应也可能是迷走神经介导的。总之，这些发现有助于越来越多的证据表明，谷氨酸通过专门的味觉和肠道受体信号传导影响多种生理功能，包括体温调节和能量稳态。
L-Glutamate is a multifunctional amino acid involved in perception of umami taste, intermediary metabolism, and excitatory neurotransmission. Recent studies have uncovered new roles for dietary glutamate in gut-brain axis activation and energy homeostasis. Glutamate receptors and their cellular transduction molecules have recently been identified in gut epithelial cells. Stimulation of gut glutamate receptors enhances the apical expression of glutamate transporters and triggers the release of signaling molecules such as nitric oxide and serotonin. Release of these signaling molecules activates vagal afferent nerve fibers and as a result different brain regions directly or indirectly targeted by vagal inputs. More generally, evidence accumulates in support of the concept that a specific brain system, especially responsive to vagal activation, is involved in sensing the postingestive effects produced by dietary glutamate. Notably, three areas of the brain, the medial preoptic area, dorsomedial nucleus of the hypothalamus, and habenular nucleus are activated by intragastric infusions of glutamate, but not by glucose or NaCl infusions. These glutamate-specific brain responses seem to depend on vagal transmission, since complete transection of the subdiaphragmatic vagal trunks abolish monosodium glutamate (MSG)-induced brain activations but not those induced by intragastric glucose infusions. Conversely, lesions to the dopaminergic neurons of the ventral tegmental area reduce behavioral preferences for sucrose, but not for umami solutions (MSG and 5′-ribonucleotides). Consistent with these findings, gastric vagotomy specifically reduces the overall intake of MSG, and intragastric infusions of MSG at 60 mM, but not of glucose or NaCl; it also induces flavor preference learning in rats. Finally, glutamate consumption produces nutrient-specific effects on metabolism and body weight. In fact, chronic ad libitum ingestion of a palatable solution of 1% (w/v) MSG by rats reduces weight gain, fat deposition, and plasma leptin levels in comparison with ingestion of plain water. Such effects may also be vagally mediated. Taken together, these findings contribute to the growing body of evidence indicating that glutamate signaling via dedicated taste and gut receptors influences multiple physiological functions including thermoregulation and energy homeostasis.
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DOI：
10.1073/pnas.89.12.5675
发表时间：
1992-06-15
影响因子：
11.1
作者：
KWONG, KK;BELLIVEAU, JW;ROSEN, BR
通讯作者：
ROSEN, BR
DOI：
10.1152/ajpgi.00232.2003
发表时间：
2004-08-01
影响因子：
4.5
作者：
Fan, MZ;Matthews, JC;Burrin, DG
通讯作者：
Burrin, DG
影响因子：
4.2
作者：
Reeds, PJ;Burrin, DG;Jahoor, F
通讯作者：
Jahoor, F
DOI：
--
发表时间：
2006
期刊：
--
影响因子：
--
作者：
J. Dimicco;D. Zaretsky
通讯作者：
J. Dimicco;D. Zaretsky