Locus Coeruleus Activity Strengthens Prioritized Memories Under Arousal
Locus Coeruleus Activity Strengthens Prioritized Memories Under Arousal
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DOI：
10.1523/jneurosci.2097-17.2017
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发表时间：
2018-02-07
影响因子：
5.3
通讯作者：
Mather, Mara
中科院分区：
文献类型：
--
作者：
Clewett, David V.;Huang, Ringo;Mather, Mara
最近的模型表明，蓝斑（LC）活动的爆发放大了神经增益，使得有限的注意力和编码资源更多地集中在唤醒下优先的心理表征上。在这里，我们测试了这一假设在人类男性和女性使用功能磁共振成像，神经黑色素MRI和瞳孔扩张，唤醒和LC活动的生物标志物。在扫描过程中，参与者进行了一个金钱激励编码任务，其中惩罚的威胁促使他们优先编码叠加对象的场景图像。惩罚的威胁会引起觉醒，并选择性地增强对目标相关场景的记忆。此外，试验水平的瞳孔放大预测更好的场景记忆的威胁下，但不相关的对象的记忆结果。功能磁共振成像分析显示，更大的威胁诱发的瞳孔扩张与LC和海马旁皮质（一个专门处理场景信息的区域）更大的场景编码活动呈正相关。在参与者中，这种LC参与目标相关编码的模式与神经黑色素信号强度相关，这提供了LC结构与认知过程中其激活模式相关的第一个证据。威胁还减少了高优先级（海马旁位置区）和低优先级（外侧枕叶皮层）类别选择性视觉皮层之间的动态功能连接，预测增加记忆选择性的方式。总之，这些研究结果支持的想法，唤醒下，LC活动选择性地加强优先级的记忆表征调制本地和功能网络级的信息处理模式。
Recent models posit that bursts of locus ceruleus (LC) activity amplify neural gain such that limited attention and encoding resources focus even more on prioritized mental representations under arousal. Here, we tested this hypothesis in human males and females using fMRI, neuromelanin MRI, and pupil dilation, a biomarker of arousal and LC activity. During scanning, participants performed a monetary incentive encoding task in which threat of punishment motivated them to prioritize encoding of scene images over superimposed objects. Threat of punishment elicited arousal and selectively enhanced memory for goal-relevant scenes. Furthermore, trial-level pupil dilations predicted better scene memory under threat, but were not related to object memory outcomes. fMRI analyses revealed that greater threat-evoked pupil dilations were positively associated with greater scene encoding activity in LC and parahippocampal cortex, a region specialized to process scene information. Across participants, this pattern of LC engagement for goal-relevant encoding was correlated with neuromelanin signal intensity, providing the first evidence that LC structure relates to its activation pattern during cognitive processing. Threat also reduced dynamic functional connectivity between high-priority (parahippocampal place area) and lower-priority (lateral occipital cortex) category-selective visual cortex in ways that predicted increased memory selectivity. Together, these findings support the idea that, under arousal, LC activity selectively strengthens prioritized memory representations by modulating local and functional network-level patterns of information processing.