Laboratory of Neurobiology of Appetite, Department of Pharmacology, CINVESTAV, 07360, Mexico City, Mexico.
Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA.
Cell Mol Life Sci. 2020 Sep;77(18):3469-3502. doi: 10.1007/s00018-020-03458-2. Epub 2020 Jan 31.
Throughout the animal kingdom sucrose is one of the most palatable and preferred tastants. From an evolutionary perspective, this is not surprising as it is a primary source of energy. However, its overconsumption can result in obesity and an associated cornucopia of maladies, including type 2 diabetes and cardiovascular disease. Here we describe three physiological levels of processing sucrose that are involved in the decision to ingest it: the tongue, gut, and brain. The first section describes the peripheral cellular and molecular mechanisms of sweet taste identification that project to higher brain centers. We argue that stimulation of the tongue with sucrose triggers the formation of three distinct pathways that convey sensory attributes about its quality, palatability, and intensity that results in a perception of sweet taste. We also discuss the coding of sucrose throughout the gustatory pathway. The second section reviews how sucrose, and other palatable foods, interact with the gut-brain axis either through the hepatoportal system and/or vagal pathways in a manner that encodes both the rewarding and of nutritional value of foods. The third section reviews the homeostatic, hedonic, and aversive brain circuits involved in the control of food intake. Finally, we discuss evidence that overconsumption of sugars (or high fat diets) blunts taste perception, the post-ingestive nutritional reward value, and the circuits that control feeding in a manner that can lead to the development of obesity.
在整个动物王国中，蔗糖是最可口和最受欢迎的味觉物质之一。从进化的角度来看，这并不奇怪，因为它是主要的能量来源。然而，过量摄入蔗糖会导致肥胖和一系列相关疾病，包括 2 型糖尿病和心血管疾病。在这里，我们描述了参与摄入蔗糖决策的三个生理处理水平：舌头、肠道和大脑。第一节描述了甜味识别的外周细胞和分子机制，这些机制投射到大脑的高级中枢。我们认为，用蔗糖刺激舌头会引发三种不同的途径，这些途径传递关于其质量、可口性和强度的感官属性，从而产生甜味的感知。我们还讨论了蔗糖在味觉通路中的编码方式。第二节综述了蔗糖和其他可口食物如何通过门静脉系统和/或迷走神经途径与肠道-大脑轴相互作用，以一种既能编码食物的奖赏性又能编码其营养价值的方式。第三节综述了参与食物摄入控制的稳态、愉悦和厌恶大脑回路。最后，我们讨论了过量摄入糖（或高脂肪饮食）会使味觉感知、摄入后的营养奖赏价值以及控制进食的回路迟钝的证据，这种情况可能导致肥胖的发生。
