A stable sparse fear memory trace in human amygdala.
A stable sparse fear memory trace in human amygdala.
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DOI：
10.1523/jneurosci.1524-11.2011
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发表时间：
2011-06-22
期刊：
影响因子：
--
通讯作者：
Dolan RJ
中科院分区：
文献类型：
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作者：
Bach DR;Weiskopf N;Dolan RJ
巴甫洛夫恐惧条件反射在不同物种中高度保守，提供了一种强大的厌恶学习模式。在啮齿动物中，恐惧记忆在杏仁核的影响下被储存并重新激活。没有证据表明灵长类存在相同的机制，有人提出了一种相反的机制，即灵长类杏仁核只在厌恶学习的初始阶段起作用，随后将恐惧记忆割让给杏仁外区域。在这里，我们通过利用人类高分辨率功能磁共振成像结合多变量方法来重新研究这个问题。通过假设稀疏神经编码，我们表明，在个体受试者水平上，可以区分杏仁核基底外侧核和中央皮质核团对条件性(CS+和CS−)刺激的反应。这种辨别的强度随着时间的推移而增加，并与恐惧的行为表达紧密相连，与稳定的恐惧记忆痕迹的表达一致。这些数据强调，人类的基底外侧核和中央皮质杏仁核支持最初的学习，以及更长时间的持久恐惧记忆存储。这里通过多变量模式分类揭示了恐惧的稀疏神经元表示，解释了为什么在以前的人类研究中，持久的记忆痕迹被证明是难以捉摸的。
Pavlovian fear conditioning is highly conserved across species, providing a powerful model of aversive learning. In rodents, fear memory is stored and reactivated under the influence of the amygdala. There is no evidence for an equivalent mechanism in primates, and an opposite mechanism is proposed whereby primate amygdala contributes only to an initial phase of aversive learning, subsequently ceding fear memory to extra-amygdalar regions. Here, we re-examine this question by exploiting human high-resolution functional magnetic resonance imaging in conjunction with multivariate methods. By assuming a sparse neural coding we show it is possible, at an individual subject level, to discriminate responses to conditioned (CS+ and CS−) stimuli in both basolateral and centro-cortical amygdala nuclei. The strength of this discrimination increased over time and was tightly coupled to the behavioural expression of fear, consistent with an expression of a stable fear memory trace. These data highlight that the human basolateral and centro-cortical amygdala support initial learning as well a more time enduring fear memory storage. A sparse neuronal representation for fear, here revealed by multivariate pattern classification, resolves why an enduring memory trace has proved elusive in previous human studies.