GUSTATORY REWARD AND DOPAMINE IN THE NUCLEUS ACCUMBENS

描述(摘自申请者的摘要)：味觉刺激，尤其是那些 对人类来说是甜味的，启动并维持进食行为。他们也 提供足够的奖励来支持大多数动物的习得行为 来确定食物的位置。与摄食(和其他生物)有关的奖励机制 驱动器)通常与中脑边缘多巴胺(DA)系统相关联，并且 尤其是伏隔核。然而，伏隔膜的功能 DA的回报仍不清楚。品味提供了一个合理的工具来检查 中央奖励机制。皂基化学物质很容易量化，它们是 通过单一的、描述良好的感觉通道进行转换，它们可以 与它们的营养后果无关。相反，这种测试 中央奖励系统可以揭示味觉的一个中心难题 生理学--如何调和味觉的享乐品质 纯粹的感官特征。尽管两者的口味有很大的重叠 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 设计目的是：1)研究皂苷蔗糖是否激活中伏隔核DA 在假喂食过程中以浓度依赖的方式检测神经元；2)评估 慢性减肥过程中舔蔗糖对NAC DA的影响 奖赏敏化；以及3)检测DI和D2多巴胺能神经元的贡献 NAC在行为和神经化学调节中的作用机制 在正常体重和体重不足的大鼠中，激活与蔗糖摄入有关。 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进行局部灌流。这个 这种调查的长期目标是了解与食物有关的 口头刺激会产生奖励。这一知识直接与 认识正常进食行为的控制和对疾病的控制 与这一基本行为有关，如肥胖、神经性厌食症、暴食症 神经质和暴饮暴食障碍。

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.