Renewal of conditioned fear in a novel context is associated with hippocampal activation and connectivity
Renewal of conditioned fear in a novel context is associated with hippocampal activation and connectivity
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DOI：
10.1093/scan/nsw047
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发表时间：
2016-09-01
影响因子：
4.2
通讯作者：
Merz, C. J.
中科院分区：
文献类型：
--
作者：
Hermann, A.;Stark, R.;Merz, C. J.
在以暴露为基础的焦虑症治疗中，恐惧的回归是一个严重的问题。当在新的环境中再次遇到条件刺激时，恐惧反应可能会发生更新。在啮齿动物身上的发现证实了海马体在新环境下条件恐惧更新中的作用，但它还有待于在人类身上进行研究。46名健康男性参加了为期2天的情境依赖的线索恐惧条件反射范式，其中包括恐惧习得、消退学习（第1天）和后天习得、消退和新情境中的消退回忆。条件评价、皮肤电导反应（SCRs）和血氧水平依赖性反应作为因变量。情境依赖性恐惧更新反映在条件较强的scr中。在习得情境下，条件scr更新较高的个体表现出更强的恐惧回路激活。海马体的激活区分了小说情境下的条件反应和消失情境下的条件反应。在新环境下条件scr更新较强的个体，海马激活灶与恐惧和消退网络结构的有效连通性增加。这些结果概述了海马体的关键作用及其在人类新环境下条件恐惧更新中的连通性，并可能对焦虑障碍的暴露治疗具有重要意义。
Return of fear is a serious problem in exposure-based treatments of anxiety disorders. Renewal of the fear response may occur when re-encountering the conditioned stimulus within a novel context. Findings in rodents underpin the hippocampus' role in conditioned fear renewal in novel contexts, but it has yet to be investigated in humans. Forty-six healthy men took part in a 2-day, context-dependent, cued fear conditioning paradigm with fear acquisition, extinction learning (day 1) and extinction recall in the acquisition, extinction and a novel context one day later. Conditioned evaluative, skin conductance responses (SCRs) and blood-oxygen-level-dependent responses served as dependent variables. Context-dependent fear renewal was reflected in stronger conditioned SCRs. In the acquisition context, individuals with a higher renewal of conditioned SCRs showed stronger activation of the fear circuit. Hippocampal activation distinguished conditioned responding in the novel compared with the extinction context. Individuals with a stronger renewal of conditioned SCRs in the novel context showed increased effective connectivity of hippocampal activation foci with structures in the fear and extinction network. These results outline the pivotal role of the hippocampus and its connectivity in conditioned fear renewal in a novel context in humans and might have important implications for exposure therapy in anxiety disorders.