Psychophysical, computational, and neurochemical analysis of gustatory reward

味觉奖励的心理物理学、计算和神经化学分析

• 批准号: 308-2011
• 负责人: Shizgal, Peter
• 金额: $ 2.26万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=473307
• 关键词: Psychophysical; computational; neurochemical; analysis; gustatory

To succeed in their struggle for survival and reproductive success, animals must make good choices about which goals to pursue and how much effort to invest in attaining them. Benefits and costs must be weighed appropriately in the quest for crucial resources, such as food and water. The taste system, an important input to such decisions, provides information about the nutrient content of foods and warnings about potential toxins. Much has been learned about the cells in the mouth and on the tongue that give rise to the sense of taste and about the pathways that relay signals from these cells to the brain and process them. Much less is known about the brain circuits that translate taste information into decisions about food-seeking behaviour. These circuits are the subject of the proposed experiments, which concern the transformation of sensory information (taste and "mouth feel") into a subjective assessment of value. Given the animal's current physiological state and the work and risk involved in harvesting a particular food, how much is that food worth? I have developed a mathematical model that describes how the value of the food is computed. Using behavioural tests derived from the model, we can determine which of the many influences on food-seeking behaviour are affected by changes in need states, drugs, and brain circuits. The proposed experiments assess the effects of both short- and long-term food shortages on the perceived value of sugar and fat and on the effort rats are willing to invest to obtain foods rich in these substances. We will test the hypothesis that reward-related gustatory information is carried by a particular set of brain pathways, the projections from the pontine parabrachial nucleus to the basal forebrain. We will also study the role of dopamine-containing brain cells in the valuation of foods and of the effort required to obtain them. Working out the brain circuity involved in the evaluation and pursuit of food rewards is a necessary step towards understanding the mechanisms underlying foraging behaviour and should provide information useful to understanding how our contemporary environment, in which food is abundant, highly available, rich, and relatively inexpensive, is so conducive to the development of obesity.

为了在为生存和繁殖成功而进行的斗争中取得成功，动物必须做出正确的选择，决定追求哪些目标，以及投入多少努力来实现这些目标。在寻求食物和水等关键资源时，必须适当权衡收益和成本。味觉系统是这类决策的重要输入，它提供有关食物营养成分的信息和关于潜在毒素的警告。关于口腔和舌头中产生味觉的细胞，以及将信号从这些细胞传递到大脑并对其进行处理的路径，人们已经了解了很多。对于将味觉信息转化为关于觅食行为的决定的大脑回路，我们知之甚少。这些回路是拟议中的实验的主题，该实验涉及将感觉信息(味觉和口感)转化为对价值的主观评估。考虑到动物目前的生理状态，以及收获特定食物所涉及的工作和风险，这种食物值多少钱？我开发了一个数学模型，描述了食物的价值是如何计算出来的。使用从该模型衍生的行为测试，我们可以确定对食物寻找行为的许多影响中的哪一种受到需求状态、药物和大脑回路的变化的影响。拟议的实验评估了短期和长期食物短缺对糖和脂肪的感知价值以及大鼠愿意投资获得富含这些物质的食物的影响。我们将检验这一假设，即奖赏相关的味觉信息是由一组特定的大脑通路携带的，即从桥臂旁核到基底前脑的投射。我们还将研究含有多巴胺的脑细胞在食物估价中的作用以及获得食物所需的努力。找出评估和追求食物奖励的大脑回路是理解觅食行为潜在机制的必要步骤，应该提供有助于理解我们当代环境的有用信息，在这个环境中，食物丰富、高度可用、丰富且相对便宜，是如何如此有利于肥胖的发展。