海马网络模块性与精神分裂症的关系记忆功能障碍有关。
Hippocampal Network Modularity Is Associated With Relational Memory Dysfunction in Schizophrenia.
机构信息
Department of Psychiatry, Vanderbilt University Medical Center, Nashville, Tennessee.
Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee.
出版信息
Biol Psychiatry Cogn Neurosci Neuroimaging. 2018 May;3(5):423-432. doi: 10.1016/j.bpsc.2018.02.001. Epub 2018 Feb 22.
BACKGROUND
Functional dysconnectivity has been proposed as a major pathophysiological mechanism for cognitive dysfunction in schizophrenia. The hippocampus is a focal point of dysconnectivity in schizophrenia, with decreased hippocampal functional connectivity contributing to the marked memory deficits observed in patients. Normal memory function relies on the interaction of complex corticohippocampal networks. However, only recent technological advances have enabled the large-scale exploration of functional networks with accuracy and precision.
METHODS
We investigated the modularity of hippocampal resting-state functional networks in a sample of 45 patients with schizophrenia spectrum disorders and 38 healthy control subjects. Modularity was calculated for two distinct functional networks: a core hippocampal-medial temporal lobe cortex network and an extended hippocampal-cortical network. As hippocampal function differs along its longitudinal axis, follow-up analyses examined anterior and posterior networks separately. To explore effects of resting network function on behavior, we tested associations between modularity and relational memory ability. Age, sex, handedness, and parental education were similar between groups.
RESULTS
Network modularity was lower in schizophrenia patients, especially in the posterior hippocampal network. Schizophrenia patients also showed markedly lower relational memory ability compared with control subjects. We found a distinct brain-behavior relationship in schizophrenia that differed from control subjects by network and anterior/posterior division-while relational memory in control subjects was associated with anterior hippocampal-cortical modularity, schizophrenia patients showed an association with posterior hippocampal-medial temporal lobe cortex network modularity.
CONCLUSIONS
Our findings support a model of abnormal resting-state corticohippocampal network coherence in schizophrenia, which may contribute to relational memory deficits.
背景
功能连接失调被认为是精神分裂症认知功能障碍的主要病理生理机制。海马体是精神分裂症连接失调的焦点，海马体功能连接的减少导致患者出现明显的记忆缺陷。正常的记忆功能依赖于复杂的皮质-海马网络的相互作用。然而，只有最近的技术进步才使得大规模探索具有准确性和精密度的功能网络成为可能。
方法
我们在 45 名精神分裂症谱系障碍患者和 38 名健康对照者的样本中研究了海马体静息状态功能网络的模块性。为两个不同的功能网络计算了模块性：一个核心海马体-内侧颞叶皮层网络和一个扩展的海马体-皮层网络。由于海马体的功能沿着其纵轴而有所不同，后续分析分别检查了前网络和后网络。为了探索静息网络功能对行为的影响，我们测试了模块性与关系记忆能力之间的关联。年龄、性别、利手和父母教育在组间相似。
结果
精神分裂症患者的网络模块性较低，尤其是在后海马体网络中。与对照组相比，精神分裂症患者的关系记忆能力也明显较低。我们在精神分裂症中发现了一种独特的脑-行为关系，这种关系与对照组不同，表现在网络和前/后分区上——而在对照组中，关系记忆与前海马体-皮层的模块性相关，精神分裂症患者则与后海马体-内侧颞叶皮层网络的模块性相关。
结论
我们的研究结果支持精神分裂症静息状态皮质-海马网络相干性异常的模型，这可能导致关系记忆缺陷。
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