Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark; DTU Compute, Cognitive Systems, Technical University of Denmark, Denmark; Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Roskilde, Denmark; iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Denmark.
DTU Compute, Cognitive Systems, Technical University of Denmark, Denmark.
Schizophr Res. 2018 Jul;197:328-336. doi: 10.1016/j.schres.2018.01.026. Epub 2018 Feb 1.
22q11.2 deletion syndrome (22q11.2DS) is one of the most common copy number variants and confers a markedly increased risk for schizophrenia. As such, 22q11.2DS is a homogeneous genetic liability model which enables studies to delineate functional abnormalities that may precede disease onset. Mismatch negativity (MMN), a brain marker of change detection, is reduced in people with schizophrenia compared to healthy controls. Using dynamic causal modelling (DCM), previous studies showed that top-down effective connectivity linking the frontal and temporal cortex is reduced in schizophrenia relative to healthy controls in MMN tasks. In the search for early risk-markers for schizophrenia we investigated the neural basis of change detection in a group with 22q11.2DS. We recorded high-density EEG from 19 young non-psychotic 22q11.2 deletion carriers, as well as from 27 healthy non-carriers with comparable age distribution and sex ratio, while they listened to a sequence of sounds arranged in a roving oddball paradigm. Despite finding no significant reduction in the MMN responses, whole-scalp spatiotemporal analysis of responses to the tones revealed a greater fronto-temporal N1 component in the 22q11.2 deletion carriers. DCM showed reduced intrinsic connection within right primary auditory cortex as well as in the top-down, connection from the right inferior frontal gyrus to right superior temporal gyrus for 22q11.2 deletion carriers although not surviving correction for multiple comparison. We discuss these findings in terms of reduced adaptation and a general increased sensitivity to tones in 22q11.2DS.
22q11.2 缺失综合征(22q11.2DS)是最常见的拷贝数变异之一,显著增加了精神分裂症的风险。因此,22q11.2DS 是一种均质的遗传易感性模型,使研究能够描绘可能在疾病发作之前出现的功能异常。失匹配负波(MMN)是大脑变化检测的标志物,与健康对照组相比,精神分裂症患者的 MMN 减少。使用动态因果建模(DCM),先前的研究表明,在 MMN 任务中,与健康对照组相比,连接额叶和颞叶的自上而下的有效连接减少。为了寻找精神分裂症的早期风险标志物,我们在一组 22q11.2DS 患者中研究了变化检测的神经基础。我们从 19 名年轻的非精神病 22q11.2 缺失携带者以及 27 名年龄分布和性别比例相当的健康非携带者中记录了高密度 EEG,同时他们听了一个在漫游奇异性范式中排列的声音序列。尽管 MMN 反应没有明显减少,但对音调反应的全头皮时空分析显示,22q11.2 缺失携带者的额颞 N1 成分更大。DCM 显示 22q11.2 缺失携带者右侧初级听觉皮层以及自上而下的右额下回到右颞上回的连接的内在连接减少,尽管未通过多次比较校正而幸存。我们根据 22q11.2DS 中适应性降低和对音调的普遍敏感性增加来讨论这些发现。