McCutcheon James Edgar
Dept. of Cell Physiology and Pharmacology, Maurice Shock Medical Sciences Building, University of Leicester, University Road, Leicester LE1 9HN, United Kingdom.
Physiol Behav. 2015 Dec 1;152(Pt B):408-15. doi: 10.1016/j.physbeh.2015.05.003. Epub 2015 May 7.
Acquiring enough food to meet energy expenditure is fundamental for all organisms. Thus, mechanisms have evolved to allow foods with high nutritional value to be readily detected, consumed, and remembered. Although taste is often involved in these processes, there is a wealth of evidence supporting the existence of taste-independent nutrient sensing. In particular, post-ingestive mechanisms arising from the arrival of nutrients in the gut are able to drive food intake and behavioural conditioning. The physiological mechanisms underlying these effects are complex but are believed to converge on mesolimbic dopamine signalling to translate post-ingestive sensing of nutrients into reward and reinforcement value. Discerning the role of nutrition is often difficult because food stimulates sensory systems and post-ingestive pathways in concert. In this mini-review, I discuss the various methods that may be used to study post-ingestive processes in isolation including sham-feeding, non-nutritive sweeteners, post-ingestive infusions, and pharmacological and genetic methods. Using this structure, I present the evidence that dopamine is sensitive to nutritional value of certain foods and examine how this affects learning about food, the role of taste, and the implications for human obesity.
获取足够的食物以满足能量消耗对所有生物体来说都是至关重要的。因此，生物进化出了相应机制，以便能轻松检测、摄取并记住高营养价值的食物。尽管味觉通常参与这些过程，但有大量证据支持存在与味觉无关的营养感知。特别是，营养物质进入肠道后产生的摄食后机制能够驱动食物摄入和行为条件反射。这些效应背后的生理机制很复杂，但据信它们会汇聚到中脑边缘多巴胺信号传导，将摄食后对营养物质的感知转化为奖励和强化价值。由于食物会同时刺激感觉系统和摄食后通路，所以常常难以辨别营养的作用。在这篇小型综述中，我讨论了可用于单独研究摄食后过程的各种方法，包括假饲、非营养性甜味剂、摄食后输注以及药理学和遗传学方法。基于此结构，我展示了多巴胺对某些食物营养价值敏感的证据，并探讨了这如何影响对食物的学习、味觉的作用以及对人类肥胖的影响。
