条件性恐惧记忆消退的提取干预范式及其作用的神经机制

基于记忆再巩固理论的恐惧记忆提取干预范式被证明可以有效消退恐惧记忆, 能克服传统消退容易复发的缺点。该范式通过单独呈现条件刺激激活原有恐惧记忆, 使记忆重返不稳定状态, 随后在再巩固时间窗内实施干预则能改写原有记忆。目前该范式起作用的神经机制尚不明确, 本文在现有的人类研究和动物研究基础上, 总结了杏仁核、前额叶和海马三个脑区在提取干预过程中的作用, 以及该领域研究的争议点, 为之后的研究提供思路。

The effect of retrieval intervention paradigm to conditioned fear extinction and its neural mechanism

The memory reconsolidation theory holds that consolidated memories can be reactivated into an unstable state again, which is called the reconsolidation process. During this period, the activated memories are susceptive to new information and therefore, the interruption of it can update or eliminate original memories. Behavioral or pharmacological interventions after memory reactivation are proved to be an effective way to extinguish fear memories and prevent relapse. The behavioral intervention, which is the so-called retrieval-extinction paradigm can eliminate conditioned fear through applying extinction training during the reconsolidation time window. The neural mechanisms of this effect, however, are still largely unknown. Based on reviewing present studies in animals and humans, we concluded the critical brain areas which were proved to be playing an important part in retrieval extinction process and their effect mechanisms, including hippocampus, prefrontal cortex and amygdala. Furthermore, we summarized the controversial points in theories and manipulations in order to provide insights for future explorations.