Auditory-evoked spike firing in the lateral amygdala and Pavlovian fear conditioning: Mnemonic code or fear bias?
Auditory-evoked spike firing in the lateral amygdala and Pavlovian fear conditioning: Mnemonic code or fear bias?
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DOI：
10.1016/s0896-6273(03)00728-1
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发表时间：
2003-12-04
期刊：
影响因子：
16.2
通讯作者：
Maren, S
中科院分区：
文献类型：
--
作者：
Goosens, KA;Hobin, JA;Maren, S
杏仁核的神经可塑性已经成为巴甫洛夫恐惧记忆的候选底物。根据这一观点，条件刺激(CS)诱发的活动代表了一种启动恐惧行为表达的助记代码。然而，恐惧状态可能会非关联性地增强感觉处理，偏向杏仁核神经元中CS诱发的活动。在这里，我们描述了在大鼠杏仁外侧核(LA)分离听觉CS诱发的棘波放电和条件恐惧行为和LA兴奋性的实验。我们发现，条件性冻结和LA兴奋性增加的表达既不是CS诱发的棘波放电条件性增加的必要条件，也不是充分条件。相反，条件反射诱发的棘波放电的条件性改变完全由CS的关联史决定。因此，我们的数据支持这样一个模型，即LA中的关联活动编码恐惧记忆，并有助于表达习得的恐惧行为。
Amygdala neuroplasticity has emerged as a candidate substrate for Pavlovian fear memory. By this view, conditional stimulus (CS)-evoked activity represents a mnemonic code that initiates the expression of fear behaviors. However, a fear state may nonassociatively enhance sensory processing, biasing CS-evoked activity in amygdala neurons. Here we describe experiments that dissociate auditory CS-evoked spike firing in the lateral amygdala (LA) and both conditional fear behavior and LA excitability in rats. We found that the expression of conditional freezing and increased LA excitability was neither necessary nor sufficient for the expression of conditional increases in CS-evoked spike firing. Rather, conditioning-related changes in CS-evoked spike firing were solely determined by the associative history of the CS. Thus, our data support a model in which associative activity in the LA encodes fear memory and contributes to the expression of learned fear behaviors.