School of Psychology, The University of New South Wales, Sydney, Australia.
PLoS One. 2013 May 10;8(5):e58701. doi: 10.1371/journal.pone.0058701. Print 2013.
The hippocampus is part of a neural network which regulates the renewal of fear following extinction. Both the ventral (VH) and dorsal (DH) hippocampus have been shown to be necessary for renewal, however the critical receptors and neurotransmitters mediating these contributions are poorly understood. One candidate mechanism is the kappa opioid receptor (KOR) system, which has been implicated in fear learning and anxiety. Here we examined the effect of the KOR antagonist norbinaltorphamine hydrochloride (norBNI), infused into either the VH or DH, on the renewal of extinguished fear. We found that an infusion of norBNI into the VH significantly reduced the relapse of fear on test compared to that seen in saline controls (Experiment 1), while similar infusions of norBNI into the DH had no effect on renewal (Experiment 2). These findings show that hippocampal KORs are involved in fear renewal and also identify a dissociation in the contribution of VH and DH KORs to the expression of renewed fear.
海马体是调节恐惧消退后恐惧更新的神经网络的一部分。腹侧（VH）和背侧（DH）海马体都被证明对更新是必要的，然而，介导这些贡献的关键受体和神经递质还知之甚少。一个候选机制是κ阿片受体（KOR）系统，它与恐惧学习和焦虑有关。在这里，我们研究了 KOR 拮抗剂 norbinaltorphamine hydrochloride（norBNI）注入 VH 或 DH 对已消退恐惧的更新的影响。我们发现，与生理盐水对照组相比，norBNI 注入 VH 可显著减少测试时恐惧的复发（实验 1），而 norBNI 类似注入 DH 对更新没有影响（实验 2）。这些发现表明海马体 KOR 参与了恐惧的更新，并且还表明 VH 和 DH KOR 对更新的恐惧表达的贡献存在差异。
