Affective neuroscience of taste reactivity

描述(申请人提供)：关于大脑机制如何引起对自然刺激的积极情感反应，人们知之甚少。该项目旨在确定伏隔核外壳中唯一能够引起对食物味道的积极情感反应的神经回路。目的研究行为情感反应，基于味觉反应范式(人类婴儿、其他灵长类动物和大鼠的味觉诱发反应[本研究])，以评估脑操作对情感反应的影响。神经化学受体识别：我们将鉴定伏隔核中负责引起对味道的正向情感反应的阿片受体亚型(S)的神经化学身份。我们将把选择性阿片激动剂微量注射到伏隔核的一个区域，在那里我们已经证明吗啡增强了对蔗糖味道的积极情感反应。然后用微量注射选择性阿片拮抗剂阻断，以确认受体亚型识别。然后将阿片类药物的作用与伏隔核中的GABA、DA和谷氨酸神经递质作用进行比较。我们期望发现伏隔阿片受体的激活在引起更多的积极情感反应(有助于增加食物摄入量)方面发挥着独特的作用。神经解剖学识别：我们将结合兴奋性毒素损伤标测和显微注射标测技术来识别引起更多积极情感反应的伏隔部位的神经解剖边界。根据初步结果，我们预计伏隔核壳的尾侧内侧区域将是主要部位。回路相互作用：最后，我们将研究伏隔核嵌入其中的更大的神经系统，特别是向靶结构的传出投射在正向情感反应中的作用。这将开始阐明产生积极情感反应的神经回路，这可能涉及人类情感障碍，涉及特定的积极情感缺陷。

DESCRIPTION (provided by applicant): Little is known about how brain mechanisms cause positive affective reactions to natural stimuli. This project aims to identify neural circuits in the shell of the nucleus accumbens that are uniquiely capable of causing increased positive affective reactions to the taste of food. Objective behavioral affective reactions, based on the taste reactivity paradigm (taste-elicted reactions of human infants, other primates, and rats [in this study]) will be studied to assess the effect of brain manipulations on affective reactions.Neurochemical receptor identity: We will identify the neurochemical identity of the opioid receptor subtype(s) in nucleus accumbens responsible for causing positive affective reactions to tastes. We will make microinjections of selective opioid agonists into a region of accumbens shell where we've shown morphine enhances positive affective reactions to the taste of sucrose. Then blockade by microinjection selective opioid antagonists will be used to confirm receptor subtype identity. Then opioid effects will be compared to GABA, DA, and glutamate neurotransmitter effects in accumbens. We expect to find that accumbens opioid receptor activation plays a unique role in causing increased positive affective reactions (contributing to increased food intake).Neuroanatomical identity: We will identify the neuroanatomical boundary of the accumbens site that causes increased positive affective reactions with a combination of excitotoxin lesion mapping and microinjection mapping techniques. We expect based on preliminary results that a caudal medial region of the shell of the nuclues accumbens will be the chief site.Circuit interactions: Finally, we will examine the larger neural system in which accumbens is embedded, specifically the role of efferent projections to target structures in positive affective reaction. This will begin to clarify the neural circuits underlying generation of positive affective reactions, which may be involved in human affective disorders that involve specific deficits of positive affect.