de Araujo Ivan E, Ren Xueying, Ferreira Jozélia G
The John B Pierce Laboratory and Department of Psychiatry, Yale University School of Medicine, 290 Congress Avenue, New Haven, CT 06519, USA.
Results Probl Cell Differ. 2010;52:69-86. doi: 10.1007/978-3-642-14426-4_7.
The gustatory system allows the brain to monitor the presence of chemicals in the oral cavity and initiate appropriate responses of acceptance or rejection. Among such chemicals are the nutrients that must be rapidly recognized and ingested for immediate oxidation or storage. In the periphery, the gustatory system consists of a highly efficient sensing mechanism, where distinct cell types express receptors that bind specifically to chemicals associated with one particular taste quality. These specialized receptors connect to the brain via dedicated pathways, the stimulation of which triggers stereotypic behavioral responses as well as neurotransmitter release in brain reward dopamine systems. However, evidence also exists in favor of the concept that the critical regulators of long-term nutrient choice are physiological processes taking place after ingestion and independently of gustation. We will appraise the hypothesis that organisms can develop preferences for nutrients independently of oral taste stimulation. Of particular interest are recent findings indicating that disrupting nutrient utilization interferes with activity in brain dopamine pathways. These findings establish the metabolic fate of nutrients as previously unanticipated reward signals that regulate the reinforcing value of foods. In particular, it suggests a role for brain dopamine reward systems as metabolic sensors, allowing for signals generated by the metabolic utilization of nutrients to regulate neurotransmitter release and food reinforcement.
味觉系统使大脑能够监测口腔中化学物质的存在，并引发相应的接受或排斥反应。这些化学物质中包括必须迅速被识别并摄取以立即氧化或储存的营养物质。在周围神经系统中，味觉系统由一种高效的传感机制组成，其中不同类型的细胞表达与特定味觉品质相关的化学物质特异性结合的受体。这些专门的受体通过特定的通路与大脑相连，对其刺激会触发刻板的行为反应以及大脑奖赏多巴胺系统中的神经递质释放。然而，也有证据支持这样一种观点，即长期营养选择的关键调节因素是摄入后发生的、独立于味觉的生理过程。我们将评估生物体可以独立于口腔味觉刺激而对营养物质产生偏好的假说。特别值得关注的是最近的研究结果，即干扰营养物质的利用会干扰大脑多巴胺通路的活动。这些发现将营养物质的代谢命运确立为以前未被预料到的奖赏信号，这些信号调节食物的强化价值。特别是，这表明大脑多巴胺奖赏系统作为代谢传感器的作用，使营养物质代谢利用产生的信号能够调节神经递质释放和食物强化。
