Background

Insomnia disorder (ID) is a prevalent sleep disorder, which seriously affects people's daily life and was found to be associated with increased frequency of sleep stage shifts. Previous findings had revealed the critical role of the nucleus accumbens (NAc) in sleep-wake transition. However, the neuroimaging studies of the NAc in patients with ID have been rare. We hypothesized that structural and functional abnormalities of the NAc would be implicated in ID.

Methods

Twenty-six ID patients and 36 matched healthy controls (HC) were included in the current study. The volumes and corresponding resting-state functional connectivity (RSFC) of the bilateral NAc were compared between the two groups. The abnormal RSFC in ID were then correlated with Pittsburgh Sleep Quality Index (PSQI).

Results

Compared with HC, ID patients showed significantly increased volume of right NAc. Several brain regions showed increased RSFC with the NAc in ID patients, such as medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), caudate and putamen. Meanwhile, the occipital gyrus and temporal gyrus showed decreased RSFC with the NAc. Additionally, the increased RSFC strength between bilateral NAc and left mPFC was significant correlated with PSQI scores in ID patients.

Conclusion

Dysfunctions of the NAc-mPFC circuit were found in ID patients, which were associated with sleep quality measured by PSQI. The two patterns of increase and decrease of RSFC in ID patients observed in our study may reflect the state of hyperarousal and potential impairment of cognitive function in the patients, respectively. It is hoped that our study focusing on NAc-mPFC circuits could provide new insights for the neural mechanisms of ID and potential novel therapeutic targets for treatment of ID patients.

中文翻译：

---

NAc-mPFC电路在失眠症中的功能障碍

背景

失眠症（ID）是一种普遍的睡眠障碍，严重影响人们的日常生活，并发现与睡眠阶段变化的频率增加有关。先前的发现已经揭示伏隔核（NAc）在睡眠-觉醒过渡中的关键作用。但是，对ID患者中NAc的神经影像学研究很少。我们假设NAc的结构和功能异常可能与ID有关。

方法

本研究包括26名ID患者和36名匹配的健康对照（HC）。在两组之间比较了双侧NAc的体积和相应的静止状态功能连通性（RSFC）。然后，ID中的异常RSFC与匹兹堡睡眠质量指数（PSQI）相关联。

结果

与HC相比，ID患者的右NAc量显着增加。在ID患者中，几个大脑区域显示NAc引起的RSFC升高，例如内侧前额叶皮层（mPFC），前扣带回皮层（ACC），尾状和壳状核。同时，枕叶和颞叶的NAFC显示RSFC降低。此外，ID患者的双侧NAc和左mPFC之间的RSFC强度增加与PSQI评分显着相关。

结论

在ID患者中发现NAc-mPFC电路功能异常，这与PSQI测量的睡眠质量有关。在我们的研究中观察到的ID患者中RSFC的增加和减少的两种模式可能分别反映了患者的过度兴奋状态和潜在的认知功能损害。希望我们专注于NAc-mPFC电路的研究可以为ID的神经机制和ID患者的潜在新治疗靶点提供新的见解。