Effects of cortisol on the laterality of the neural correlates of episodic memory
Effects of cortisol on the laterality of the neural correlates of episodic memory
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DOI：
10.1016/j.jpsychires.2007.11.008
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发表时间：
2008-10-01
影响因子：
4.8
通讯作者：
McAllister-Williams, R. Hamish
中科院分区：
文献类型：
--
作者：
Alhaj, Hamid A.;Massey, Anna E.;McAllister-Williams, R. Hamish
大脑皮层活动的偏侧性改变已经在抑郁症中表现出来。其可能的病理生理机制之一是皮质类固醇激素的作用。我们以前已经证明，内源性皮质醇浓度与健康受试者和抑郁症患者的情景记忆相关的皮层活动的不对称性相关。为了进一步研究这是否是由于皮质醇对情节记忆偏侧化的因果作用，我们研究了健康受试者外源性给予皮质醇的影响。在一项双盲交叉研究中，对23名右利手健康男性志愿者进行了测试。事件相关电位（ERP）记录在一个情节记忆任务后，为期四天的课程160毫克/天的皮质醇或安慰剂。低分辨率脑电磁断层扫描（LORETA）被用来识别参与神经认知任务的大脑区域。测量唾液样本中的皮质醇水平。安慰剂治疗后的ERP和LORETA分析显示，与成功取回相关的左侧海马旁激活显著。皮质醇导致平均早期额叶ERP电压降低，晚期右侧ERP电压均升高。Loreta认为这是由于右侧额上上级回的晚期激活显著增加。皮质醇对情景记忆成绩无显著影响。这项研究表明，外源性皮质醇导致右半球比左半球更多的正向波形，可能是由于增加了对提取产物的监控。这些结果支持皮质醇对情景记忆任务中皮层活动偏侧化的因果效应的假设。(c)2007爱思唯尔有限公司保留所有权利。
Alterations in the laterality of cortical activity have been shown in depressive illnesses. One possible pathophysiological mechanism for this is all effect of corticosteroids. We have previously demonstrated that endogenous cortisol concentrations correlate with the asymmetry of cortical activity related to episodic memory in healthy subjects and depressed patients. To further-examine whether this is due to a causal effect of cortisol on the laterality of episodic memory, we studied the effect of exogenous administration of cortisol in healthy subjects. Twenty-three right-handed healthy male volunteers were tested in a double-blind cross-over study. Event-related potentials (ERPs) were recorded during an episodic memory task following a four-day course of 160 mg/day cortisol or placebo. Low-resolution brain electromagnetic tomography (LORETA) was used to identify brain regions involved in the neurocognitive task. Cortisol levels were measured in saliva samples. ERP and LORETA analysis following placebo demonstrated significant left parahippocampal activation associated with successful retrieval. Cortisol led to a decrease in the mean early frontal ERP voltage and all increase in the late right ERP voltage. LORETA suggested this to be due to a significant increased late activation of the right superior frontal gyrus. There was no significant effect of cortisol on episodic memory performance. This study suggests that exogenous cortisol leads to more positive-going waveforms over the right than the left hemisphere, possibly due to increased monitoring of the products of retrieval. The results support the hypothesis of causal effects of cortisol on the laterality of cortical activity occurring during an episodic memory task. (c) 2007 Elsevier Ltd. All rights reserved.