Failure to deactivate in the prefrontal cortex in schizophrenia:: dysfunction of the default mode network?
Failure to deactivate in the prefrontal cortex in schizophrenia:: dysfunction of the default mode network?
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DOI：
10.1017/s0033291708003565
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发表时间：
2008-08-01
影响因子：
6.9
通讯作者：
McKenna, P. J.
中科院分区：
文献类型：
--
作者：
Pomarol-Clotet, E.;Salvador, R.;McKenna, P. J.
背景。使用工作记忆任务的功能成像研究已经记录了精神分裂症患者前额皮质（PFC）的低激活和过度激活。然而，这些研究往往未能考虑任务相关失活的潜在作用方法。 32 名慢性精神分裂症患者和 32 名年龄和性别匹配的正常对照者接受了功能性磁共振成像 (fMRI) 扫描，同时执行基线、1-back 和 2-back 版本的 n-back 任务。使用线性模型来获得组中的激活和失活图。结果。对照显示出预期额叶区域的激活。还存在集群性失活，特别是在前扣带回/腹内侧 PFC 和后扣带皮层/楔前叶。与对照组相比，精神分裂症患者的右侧背外侧前额叶皮层（DLPFC）和其他额叶区域的激活减少。前扣带回/腹内侧 PFC 中还有一个区域，患者的激活程度明显高于对照组。这代表精神分裂症患者的失活失败。未能激活是患者在 n-back 任务中表现受损的一个函数，而未能停用则对表现的依赖性较小。结论。精神分裂症患者在执行工作记忆任务期间既不能激活也不能停用。失活失败的区域位于前额叶/前扣带皮层，对应于“默认模式网络”的两个中线组成部分之一，涉及与维持自我意识相关的功能。
Background. Functional imaging studies using working memory tasks have documented both prefrontal cortex (PFC) hypo- and hyperactivation in schizophrenia. However, these studies have often failed to consider the potential role of task-related deactivation.Method. Thirty-two patients with chronic schizophrenia and 32 age- and sex-matched normal controls underwent functional magnetic resonance imaging (fMRI) scanning while performing baseline, 1-back and 2-back versions of the n-back task. Linear models were used to obtain maps of activations and deactivations in the groups.Results. The controls showed activation in the expected frontal regions. There were also clusters of deactivation, particularly in the anterior cingulate/ventromedial PFC and the posterior cingulate cortex /precuneus. Compared to the controls, the schizophrenic patients showed reduced activation in the right dorsolateral prefrontal cortex (DLPFC) and other frontal areas. There was also an area in the anterior cingulate/ventromedial PFC where the patients showed apparently greater activation than the controls. This represented a failure of deactivation in the schizophrenic patients. Failure to activate was a function of the patients' impaired performance on the n-back task, whereas the failure to deactivate was less performance dependent.Conclusions. Patients with schizophrenia show both failure to activate and failure to deactivate during performance of a working memory task. The area of failure of deactivation is in the anterior prefrontal /anterior cingulate cortex and corresponds to one of the two midline components of the 'default mode network' implicated in functions related to maintaining one's sense of self.