Caffeine-indcued uncoupling of cerebral blood flow and oxygen metabolism: A calibrated BOLD fMRI study
Caffeine-indcued uncoupling of cerebral blood flow and oxygen metabolism: A calibrated BOLD fMRI study
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DOI：
10.1016/j.neuroimage.2007.10.049
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发表时间：
2008-03-01
期刊：
影响因子：
5.7
通讯作者：
Buxton, Richard B.
中科院分区：
文献类型：
--
作者：
Perthen, Joanna E.;Lansing, Amy E.;Buxton, Richard B.
虽然功能性磁共振成像（fMRI）的基础上血氧水平依赖（BOLD）的信号变化是一个敏感的工具，映射大脑激活，定量研究的药理学药物的生理作用，单独使用fMRI是难以解释的，由于BOLD响应固有的复杂性。高碳酸血症校准的BOLD方法可能是脑功能的更强大的生理探针，提供脑血流量（CBF）和脑氧代谢率（CMRO 2）变化的测量。在这项研究中，我们实施了一个定量R-2* 的方法来评估BOLD响应，以提高重复测量的稳定性，结合校准的BOLD方法，检查CBF和CMRO 2对咖啡因摄入的响应。10名普通的咖啡因消费者在服用200毫克咖啡因剂量之前和之后进行了成像。采用双回波动脉自旋标记技术测量CBF和BOLD对视觉刺激、咖啡因消耗和轻度高碳酸血症的反应。对于由视觉刺激的CBF激活定义的感兴趣区域，结果是：高碳酸血症增加CBF（+46.6%，+/- 11.3，平均值和标准误），视觉刺激增加了CBF（+47.9%，+/- 2.9）和CMRO 2（+20.7%，+/- 1.4），咖啡因降低CBF（-34.5%，+/- 2.6），CMRO 2无显著变化（+5.2%，+/- 6.4）。CBF和CMRO 2之间的耦合是显着不同的视觉刺激相比，咖啡因的消费。使用R-2* 的校准BOLD方法是评估CBF和CMRO 2对药物干预的反应变化的有前途的方法。(c)2007年爱思唯尔公司All rights reserved.
Although functional MRI (fMRI) based on blood oxygenation level-dependent (BOLD) signal changes is a sensitive tool for mapping brain activation, quantitative studies of the physiological effects of pharmacological agents using fMRI alone are difficult to interpret due to the complexities inherent in the BOLD response. Hypercapnia-calibrated BOLD methodology is potentially a more powerful physiological probe of brain function, providing measures of the changes in cerebral blood flow (CBF) and the cerebral metabolic rate of oxygen (CMRO2). In this study, we implemented a quantitative R-2* approach for assessing the BOLD response to improve the stability of repeated measurements, in combination with the calibrated BOLD method, to examine the CBF and CMRO2 responses to caffeine ingestion. Ten regular caffeine consumers were imaged before and after a 200-mg caffeine dose. A dual-echo arterial spin labeling technique was used to measure CBF and BOLD responses to visual stimulation, caffeine consumption and mild hypercapnia. For a region of interest defined by CBF activation to the visual stimulus, the results were: hypercapnia increased CBF (+46.6%, +/- 11.3, mean and standard error), visual stimulation increased both CBF (+47.9%, +/- 2.9) and CMRO2 (+20.7%, +/- 1.4), and caffeine decreased CBF (-34.5%, +/- 2.6) with a non-significant change in CMRO2 (+5.2%, +/- 6.4). The coupling between CBF and CMRO2 was significantly different in response to visual stimulation compared to caffeine consumption. A calibrated BOLD methodology using R-2* is a promising approach for evaluating CBF and CMRO2 changes in response to pharmacological interventions. (c) 2007 Elsevier Inc. All rights reserved.