睡眠剥夺影响恐惧记忆巩固的认知神经机制：静息态低频波动振幅分析

Neural mechanisms underlying fear memory consolidation influenced by sleep deprivation using the fraction amplitude of low-frequency fluctuations as marker

恐惧是人类的基本情绪,在人类生存和适应中发挥着重要的作用.先前的研究表明,睡眠剥夺会对恐惧记忆巩固过程产生影响,然而睡眠剥夺影响恐惧记忆巩固的认知神经机制并不清楚.为此,本研究采用了功能性磁共振技术探究睡眠剥夺影响恐惧记忆巩固的认知神经基础.行为结果发现,相对于控制组,睡眠剥夺组在恐惧习得过程中有更大的主观恐惧和皮肤电反应;脑成像结果发现,恐惧记忆巩固中,睡眠剥夺组增强了杏仁核的活动,减弱了腹内侧前额叶的活动;进一步的相关分析表明,睡眠剥夺组杏仁核活动变化程度与个体恐惧习得效果呈现显著的正相关,而控制组腹内侧前额叶活动变化程度与个体恐惧习得效果呈现显著的正相关.这些结果表明,睡眠剥夺可能削弱了恐惧记忆巩固过程中腹内侧前额叶对杏仁核自上而下的调节能力.

Fear is a biologically adaptive response to an environmental threat, and fear learning plays a key role in adaptive function. Sleep deprivation （SD） serves a crucial role in the process of fear memory consolidation. However, the impact of sleep deprivation on the acquisition of fear and subsequent fear memory consolidation remains unclear. Thus, the present study measured human brain activity before and after fear acquisition under conditions of 24 h of sleep deprivation and normal sleep using resting-state functional magnetic resonance imaging. Behaviorally, the SD group exhibited greater fear ratings and skin conductance responses （SCR） than the control group at the fear acquisition stage. Critically, neuroimaging results revealed that at the fear memory consolidation stage, amygdala exhibited increased activity in the SD group, whereas ventromedial prefrontal cortex （vmPFC） exhibited increased activity in the control group. Moreover, at the fear acquisition stage, the change in the activity in the amygdala during fear memory consolidation was positively correlated with fear ratings and SCR in the SD group. However, at the fear acquisition stage, the change in activity in the vmPFC was positively correlated with fear ratings in the control group. Taken together, these findings suggest that SD may weaken the top-down ability of the vmPFC to regulate the amygdala during fear memory consolidation.