Dopamine Enhances Item Novelty Detection via Hippocampal and Associative Recall via Left Lateral Prefrontal Cortex Mechanisms
Dopamine Enhances Item Novelty Detection via Hippocampal and Associative Recall via Left Lateral Prefrontal Cortex Mechanisms
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DOI：
10.1523/jneurosci.0495-19.2019
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发表时间：
2019-10-02
影响因子：
5.3
通讯作者：
Sommer, Tobias
中科院分区：
文献类型：
--
作者：
Clos, Mareike;Bunzeck, Nico;Sommer, Tobias
额-纹状体回路参与项目和联想记忆检索以及通过检索实践稳定记忆表明，人类存储记忆的检索和重新编码可能依赖于多巴胺能机制。我们在一项安慰剂对照的药理学fMRI研究中对这些假设进行了检验，该研究在53名健康男女中使用2 mg D2拮抗剂氟哌啶醇急性给药，然后对先前编码的图片-单词对进行线索联想回忆任务。此外，提示联想回忆重复3天后，没有药物干预的扫描仪外。多巴胺能调节显着提高联想回忆性能和识别准确性的口头项目。此外，我们观察到一个显着的多巴胺效应的重新编码的增加特异性的联想记忆从第一到第二线索联想回忆。氟哌啶醇下更好的联想记忆与左侧前额叶皮层和右侧顶叶皮层的更高活动有关，这表明多巴胺通过增加额顶叶监测过程的招募来促进联想检索。相比之下，氟哌啶醇下口头项目的识别能力提高反映在海马体中的新奇检测增强和显着性网络的活动增加。总之，这些结果表明多巴胺对联想回忆和项目识别的独特但伴随的积极影响，并表明通过重新编码机制的联想回忆的特异性同样被多巴胺增强。
The involvement of fronto-striatal circuits in item and associative memory retrieval as well as in the stabilization of memories by retrieval practice suggests that both retrieval and re-encoding of stored memories might rely on dopaminergic mechanisms in humans. We tested these hypotheses in a placebo-controlled pharmacological fMRI study using 2 mg of the D2 antagonist haloperidol administered acutely before a cued associative recall task of previously encoded picture-word pairs in 53 healthy humans of both sexes. The cued associative recall was moreover repeated 3 d later outside the scanner without pharmacological intervention. Dopaminergic modulation significantly improved associative recall performance and recognition accuracy of verbal items. Moreover, we observed a significant dopamine effect on re-encoding in terms of increased specificity of associative memories from the first to the second cued associative recall. Better association memory under haloperidol was linked with higher activity in the left lateral prefrontal cortex and right parietal cortex, suggesting that dopamine facilitates associative retrieval through increased recruitment of frontoparietal monitoring processes. In contrast, improved recognition of verbal items under haloperidol was reflected by enhanced novelty detection in the hippocampus and increased activity in saliency networks. Together, these results show distinct but concomitant positive effects of dopamine on associative recall and item recognition and suggest that the specificity of associative recall through re-encoding mechanisms is likewise augmented by dopamine.