Which Cue to "Want?" Central Amygdala Opioid Activation Enhances and Focuses Incentive Salience on a Prepotent Reward Cue
Which Cue to "Want?" Central Amygdala Opioid Activation Enhances and Focuses Incentive Salience on a Prepotent Reward Cue
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DOI：
10.1523/jneurosci.3875-08.2009
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发表时间：
2009-05-20
影响因子：
5.3
通讯作者：
Berridge, Kent C.
中科院分区：
文献类型：
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作者：
Mahler, Stephen V.;Berridge, Kent C.
杏仁核（CeA）的中央核有助于将学习转化为动机，在这里，我们表明，阿片类刺激CeA放大并集中学习激励显着性到一个特定的奖励线索（巴甫洛夫条件刺激，或CS）。这种动机的增强使这种暗示更有吸引力，更引人注目，更容易引起食欲和消费行为。为了揭示激励显着性的焦点，我们利用了个体差异的自动成形范式中，大鼠更喜欢接近，轻咬，嗅两个奖励相关的刺激（其优势刺激）之一。个体优势提示要么是一个预测性的CS+信号奖励（8 s金属杠杆插入），要么是提供蔗糖颗粒的金属杯（奖励源）。结果表明，CeA阿片样物质的激活，微量注射的亩激动剂DAMGO（0.1微克）选择性和可逆性增强的吸引力，无论奖励CS是大鼠的优势线索。CeA DAMGO微量注射使大鼠更积极地接近其特定的优势CS，并以近乎疯狂的消费方式积极地嗅和啃。只有优势线索作为激励目标被增强，而替代线索没有被增强。相反，通过蝇蕈醇显微注射（0.25 μ g）灭活CeA抑制了优势CS的接近、啃食和嗅闻。在CeA中，DAMGO微量注射同样增加了非条件食物摄入量，蝇蕈醇降低了非条件食物摄入量。我们的结论是，阿片类神经传递CeA有助于确定哪些环境刺激成为最“想要的”，以及如何“想要”他们成为。这可能会有力地引导寻求奖励的行为。
The central nucleus of the amygdala (CeA) helps translate learning into motivation, and here, we show that opioid stimulation of CeA magnifies and focuses learned incentive salience onto a specific reward cue (pavlovian conditioned stimulus, or CS). This motivation enhancement makes that cue more attractive, noticeable, and liable to elicit appetitive and consummatory behaviors. To reveal the focusing of incentive salience, we exploited individual differences in an autoshaping paradigm in which a rat prefers to approach, nibble, and sniff one of two reward-associated stimuli (its prepotent stimulus). The individually prepotent cue is either a predictive CS+ that signals reward (8 s metal lever insertion) or instead the metal cup that delivers sucrose pellets (the reward source). Results indicated that CeA opioid activation by microinjection of the mu agonist DAMGO (0.1 mu g) selectively and reversibly enhanced the attractiveness of whichever reward CS was that rat's prepotent cue. CeA DAMGO microinjections made rats more vigorously approach their particular prepotent CS and to energetically sniff and nibble it in a nearly frenzied consummatory manner. Only the prepotent cue was enhanced as an incentive target, and alternative cues were not enhanced. Conversely, inactivation of CeA by muscimol microinjection (0.25 mu g) suppressed approach, nibbles, and sniffs of the prepotent CS. Confirming modulation of incentive salience, unconditioned food intake was similarly increased by DAMGO microinjection and decreased by muscimol in CeA. We conclude that opioid neurotransmission in CeA helps determine which environmental stimuli become most "wanted," and how "wanted" they become. This may powerfully guide reward-seeking behavior.