Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; Zhejiang University School of Medicine, Hangzhou 310003, China.
Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; The Key Laboratory of Mental Disorder's Management in Zhejiang Province, Hangzhou 310003, China; Brain Research Institute of Zhejiang University, Hangzhou 310003, China.
J Affect Disord. 2021 Feb 1;280(Pt B):49-56. doi: 10.1016/j.jad.2020.11.072. Epub 2020 Nov 11.
Reward circuit dysfunction underlies the pathogenesis of bipolar disorder (BD). This study aims to investigate whether nucleus accumbens (NAcc) and ventromedial prefrontal cortex (vmPFC), two key reward regions for BD, have resting-state dysfunctional connectivity with other brain regions in depressed and euthymic BD.
40 bipolar depressive (DE), 20 euthymic patients (EU) and 20 healthy controls (HC) were recruited to undergo resting-state functional MRI (rs-fMRI) scanning. Seed-based functional connectivity (FC) was calculated between NAcc/vmPFC and the whole brain. Group differences were calculated and their correlations with clinical characteristics were analyzed. Support vector machine was applied to classify BD patients and HC based on the FC between the cluster of group difference and NAcc/vmPFC.
Whole brain networks of FC identified right anterior insular cortex (AIC) as a significant region with bilateral NAcc when compared among three groups. The right AIC-NAcc FC elevated in both patient groups and was highest in the EU group. Interestingly, vmPFC-based networks also identified the right AIC as a significant cluster. The right AIC-vmPFC FC elevated in both patient groups. However, FC between NAcc and vmPFC did not significantly differ BD patients from HC. Furthermore, the strength of FC between bilateral NAcc and the right AIC was positively associated with the illness course of BD. Notably, the NAcc/vmPFC-right AIC classifier acquired an accuracy of 68.75% and AUC-ROC of 78.17%.
Our sample size is modest.
Our findings indicated that elevated NAcc/vmPFC-right AIC connectivity within the reward circuit could be a neuroimaging endophenotype of BD.
双相障碍（BD）的发病机制是奖励回路功能障碍。本研究旨在探讨 BD 的两个关键奖励区域，伏隔核（NAcc）和腹内侧前额叶皮层（vmPFC），与抑郁和病情稳定的 BD 患者的其他大脑区域是否存在静息状态下功能连接障碍。
招募了 40 名双相抑郁（DE）患者、20 名病情稳定患者（EU）和 20 名健康对照（HC）进行静息态功能磁共振成像（rs-fMRI）扫描。计算 NAcc/vmPFC 与全脑之间的基于种子的功能连接（FC）。计算组间差异，并分析其与临床特征的相关性。基于组间差异与 NAcc/vmPFC 之间的 FC，应用支持向量机对 BD 患者和 HC 进行分类。
与三组相比，全脑 FC 网络确定右侧前岛叶（AIC）为与双侧 NAcc 存在显著连接的区域。两个患者组的右侧 AIC-NAcc FC 升高，且在 EU 组中最高。有趣的是，基于 vmPFC 的网络也确定了右侧 AIC 为一个显著的簇。两个患者组的右侧 AIC-vmPFC FC 升高。然而，NAcc 和 vmPFC 之间的 FC 并未将 BD 患者与 HC 明显区分开。此外，双侧 NAcc 与右侧 AIC 之间 FC 的强度与 BD 的病程呈正相关。值得注意的是，NAcc/vmPFC-右侧 AIC 分类器的准确率为 68.75%，AUC-ROC 为 78.17%。
我们的样本量不大。
我们的研究结果表明，奖励回路中升高的 NAcc/vmPFC-右侧 AIC 连接可能是 BD 的神经影像学内表型。
