Institute of Life Sciences, Ajinomoto Co., Inc.
Biol Pharm Bull. 2010;33(11):1796-9. doi: 10.1248/bpb.33.1796.
Some ingested nutrients have postingestive effects that modulate food intake and improve mood subconsciously. Here, we provide an overview of the positive postingestive effects of such nutrients, primarily L-glutamate, sugar, and lipids, with respect to behavior and brain function. We also discuss the mechanisms of brain activation resulting from signaling through the gut-brain axis. Recent studies have shown that rats prefer solutions paired with intragastric nutrients that have positive postingestive effects. Using functional magnetic resonance imaging (fMRI), we previously evaluated neural activation in response to ingested glucose, L-glutamate, and corn oil emulsion in rats and found that distinct forebrain regions were activated by these nutrients. Most of the areas activated by intragastric administration of L-glutamate were eliminated by abdominal vagotomy. On the other hand, the areas activated by intragastric administration of glucose were not affected by vagotomy. A behavioral study showed similar results for L-glutamate and glucose. These results indicate that brain activation in response to ingested nutrients occurs through distinct internal signals from the gut to the brain. Distinct regional and temporal activation in the brain determines the variety of postingestive behaviors and physiological responses.
一些摄入的营养素有餐后效应，可以潜意识地调节食物摄入和改善情绪。在这里，我们主要概述了 L-谷氨酸、糖和脂质等营养素有积极的餐后效应，以及它们对行为和大脑功能的影响。我们还讨论了通过肠道-大脑轴信号传递导致大脑激活的机制。最近的研究表明，大鼠更喜欢与具有积极餐后效应的胃内营养物质相配对的溶液。使用功能磁共振成像 (fMRI)，我们之前评估了大鼠对摄入的葡萄糖、L-谷氨酸和玉米油乳液的神经激活反应，发现这些营养物质激活了不同的前脑区域。L-谷氨酸胃内给药激活的大多数区域被腹部迷走神经切断术消除。另一方面，葡萄糖胃内给药激活的区域不受迷走神经切断术的影响。行为学研究对 L-谷氨酸和葡萄糖也得出了类似的结果。这些结果表明，大脑对摄入营养物质的激活是通过肠道向大脑传递的不同内在信号来实现的。大脑的不同区域和时间激活决定了餐后行为和生理反应的多样性。
