Nonlinear coupling between cerebral blood flow, oxygen consumption, and ATP production in human visual cortex
Nonlinear coupling between cerebral blood flow, oxygen consumption, and ATP production in human visual cortex
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DOI：
10.1073/pnas.0909711107
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发表时间：
2010-05-04
影响因子：
11.1
通讯作者：
Gao, Jia-Hong
中科院分区：
文献类型：
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作者：
Lin, Ai-Ling;Fox, Peter T.;Gao, Jia-Hong
本研究的目的是研究激活诱导的高代谢和充血，通过使用多频率（4，8和16 Hz）的反向棋盘视觉刺激范例。具体而言，我们试图（i）量化氧化和非氧化代谢途径在满足增加的能量需求方面的相对贡献[i]。例如，任务诱导的神经元激活的ATP产生（J（ATP））]和（ii）确定任务诱导的脑血流量（CBF）增加是否由氧化或非氧化代谢途径驱动。CBF、脑氧代谢率（CMRO 2;即，有氧代谢指数）和乳酸盐产生（J（Lac）;即，无氧代谢指数）通过使用生理定量MRI和光谱学方法测量。在所有刺激频率下，任务诱导的JATP增加较小（12.2-16.7%），并且由有氧代谢产生（约98%），%Delta J（ATP）与CMRO 2的百分比变化呈线性相关（r = 1.00，P < 0.001）。相反，任务诱导的CBF增加较大（51.7-65.1%），与CMRO 2的百分比变化呈负相关（r=-0.64，P=0.024），但与%Delta J（Lac）呈正相关（r = 0.91，P < 0.001）。这些结果表明：（i）任务诱导的脑激活的能量需求相对于充血反应（约60%）较小（约15%），（ii）该能量需求通过氧化代谢得到满足，以及（iii）CBF反应由氧需求以外的因素介导。
The purpose of this study was to investigate activation-induced hypermetabolism and hyperemia by using a multifrequency (4, 8, and 16 Hz) reversing-checkerboard visual stimulation paradigm. Specifically, we sought to (i) quantify the relative contributions of the oxidative and nonoxidative metabolic pathways in meeting the increased energy demands [i. e., ATP production (J(ATP))] of task-induced neuronal activation and (ii) determine whether task-induced cerebral blood flow(CBF) augmentation was driven by oxidative or nonoxidative metabolic pathways. Focal increases in CBF, cerebral metabolic rate of oxygen (CMRO2; i.e., index of aerobic metabolism), and lactate production (J(Lac); i.e., index of anaerobic metabolism) were measured by using physiologically quantitative MRI and spectroscopy methods. Task-induced increases in JATP were small (12.2-16.7%) at all stimulation frequencies and were generated by aerobic metabolism (approximately 98%), with %Delta J(ATP) being linearly correlated with the percentage change in CMRO2 (r = 1.00, P < 0.001). In contrast, task-induced increases in CBF were large (51.7-65.1%) and negatively correlated with the percentage change in CMRO2 (r=-0.64, P=0.024), but positively correlated with %Delta J(Lac) (r = 0.91, P < 0.001). These results indicate that (i) the energy demand of task-induced brain activation is small (approximately 15%) relative to the hyperemic response (approximately 60%), (ii) this energy demand is met through oxidative metabolism, and (iii) the CBF response is mediated by factors other than oxygen demand.