GUSTATORY REWARD AND DOPAMINE IN THE NUCLEUS ACCUMBENS

描述（来自申请人的摘要）：味觉刺激，特别是那些 对人类来说是甜的，启动并维持摄食行为。他们还 提供足以支持大多数动物所使用的学习行为的奖励 来寻找食物与进食有关的奖励机制（以及其他生物学机制） 驱动器）一般与中脑边缘多巴胺（DA）系统有关， 具体来说是神经核然而， 奖励方面的DA仍不清楚。品味提供了一种逻辑工具， 中央奖励机制。Sapid化学品很容易量化，它们是 通过一个单一的，描述良好的感觉通道转导，它们可以是 与其营养后果无关。相反，这种测试 中央奖励系统可以揭示味觉的核心难题， 生理学--品味的享乐品质如何与他们的 纯粹的感官特征。尽管口味之间有很大的重叠 和奖励，相对较少的实验注意力集中在 这些系统在神经水平上的相互作用。目前的实验是 目的是：1）研究甜味蔗糖是否能激活中脑DA 神经元的浓度依赖性的方式在假喂养; 2）评估 在慢性体重减轻过程中，作为 奖赏敏感化; 3）检查D1和D2多巴胺能神经元的作用。 NAc在行为和神经化学调节中的机制 在正常和体重不足的大鼠中，与蔗糖摄入相关的激活。 与以前使用全身注射的假喂养研究不同，多巴胺能 药物将通过反向微透析在NAc中局部灌注。的 这种调查的长期目标是了解与食物有关的 口头刺激产生奖赏。这些知识直接关系到 了解控制正常的摄食行为和疾病 与这种基本行为相关的疾病，如肥胖症、神经性厌食症、贪食症 神经性厌食症和暴食症

DESCRIPTION (from applicant's abstract): Gustatory stimuli, particularly those that taste sweet to humans, initiate and maintain ingestive behavior. They also provide reward sufficient to support the learned behavior used by most animals to locate food. Reward mechanisms related to feeding (and other biological drives) have been linked to the mesolimbic dopamine (DA) system in general, and to the nucleus accumbens, specifically. Nevertheless, the function of accumbens DA in reward remains unclear. Taste provides a logical tool for examining central reward mechanisms. Sapid chemicals are quantified easily, they are transduced via a single, well-described sensory channel, and they can be disassociated from their nutritional consequences. Conversely, such testing of the central reward systems can shed light on a central conundrum of gustatory physiology -how the hedonic qualities of tastes can be reconciled with their purely sensory characteristics. Despite the substantial overlap between taste and reward, relatively little experimental attention has been focused on the interaction of these systems at the neural level. The present experiments are designed to: 1) investigate whether sapid sucrose activates the mesoaccumbens DA neurons in a concentration dependent manner during sham feeding; 2) evaluate the effect sucrose licking on NAc DA during chronic weight reduction, as a model of reward sensitization; and 3) examine the contributions of DI and D2 dopaminergic mechanisms of the NAc in the mediation of both the behavioral and neurochemical activation related to sucrose ingestion in both normal and underweight rats. Unlike previous sham-feeding studies that used systemic injections, dopaminergic drugs will be perfused locally in the NAc through reverse microdialysis. The long-term objective of such an investigation is to understand how food-related oral stimuli produce reward. This knowledge is directly relevant to understanding the control of normal ingestive behavior and to the maladies related to this essential behavior, such as obesity, anorexia nervosa, bulimia nervosa, and binge eating disorder.