The lateral amygdala processes the value of conditioned and unconditioned aversive stimuli
The lateral amygdala processes the value of conditioned and unconditioned aversive stimuli
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DOI：
10.1016/j.neuroscience.2005.02.043
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发表时间：
2005-01-01
期刊：
影响因子：
3.3
通讯作者：
Ledoux, JE
中科院分区：
文献类型：
--
作者：
Blair, HT;Sotres-Bayon, F;Ledoux, JE
杏仁核对于获得和表达由预测未来惩罚的感觉刺激引起的条件性恐惧反应至关重要，但关于杏仁核是否是感知造成初级惩罚的痛苦或有害刺激的厌恶品质所必需的，存在相互矛盾的证据。为了研究这个问题，通过将一系列听觉信号（条件刺激，CS）与对一个眼睑的短暂电击序列（无条件刺激，US）配对，使老鼠产生条件恐惧。通过在训练后 24 小时进行的测试期间测量冻结反应来评估对 CS 的条件反应，通过测量训练期间眼睑震动引起的头部运动来评估对 US 的无条件反应。我们发现，训练前杏仁核外侧核（LA）的电解损伤阻止了对 CS 的条件冻结的获得，并且还显着减弱了 US 引起的无条件头部运动。同样，用 GABA-A 激动剂蝇蕈醇使双侧杏仁核失活会损害 CS 诱发的冻结的获得，并且还会减弱训练期间 US 诱发的反应。然而，当输注 NR213 受体拮抗剂艾芬地尔阻断杏仁核突触可塑性时，条件冻结的获得受到损害，但休克反应性不受影响。这些发现表明，杏仁核内的神经活动对于预测和感知有害刺激的厌恶性质都很重要，并且 LA 内的突触可塑性是在恐惧条件反射期间 CS 与 US 相关联的机制。 (c) 2005 年由 Elsevier Ltd 代表 IBRO 出版。
The amygdala is critical for acquiring and expressing conditioned fear responses elicited by sensory stimuli that predict future punishment, but there is conflicting evidence about whether the amygdala is necessary for perceiving the aversive qualities of painful or noxious stimuli that inflict primary punishment. To investigate this question, rats were fear conditioned by pairing a sequence of auditory pips (the conditioned stimulus, or CS) with a brief train of shocks to one eyelid (the unconditioned stimulus, or US). Conditioned responding to the CS was assessed by measuring freezing responses during a test session conducted 24 h after training, and unconditioned responding to the US was assessed by measuring head movements evoked by the eyelid shocks during training. We found that pre-training electrolytic lesions of the amygdala's lateral (LA) nucleus blocked acquisition of conditioned freezing to the CS, and also significantly attenuated unconditioned head movements evoked by the US. Similarly, bilateral inactivation of the amygdala with the GABA-A agonist muscimol impaired acquisition of CS-evoked freezing, and also attenuated US-evoked responses during training. However, when amygdala synaptic plasticity was blocked by infusion of the NR213 receptor antagonist ifenprodil, acquisition of conditioned freezing was impaired but shock reactivity was unaffected. These findings indicate that neural activity within the amygdala is important for both predicting and perceiving the aversive qualities of noxious stimuli, and that synaptic plasticity within LA is the mechanism by which the CS becomes associated with the US during fear conditioning. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.