FOCAL PHYSIOLOGICAL UNCOUPLING OF CEREBRAL BLOOD-FLOW AND OXIDATIVE-METABOLISM DURING SOMATOSENSORY STIMULATION IN HUMAN-SUBJECTS
FOCAL PHYSIOLOGICAL UNCOUPLING OF CEREBRAL BLOOD-FLOW AND OXIDATIVE-METABOLISM DURING SOMATOSENSORY STIMULATION IN HUMAN-SUBJECTS
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DOI：
10.1073/pnas.83.4.1140
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发表时间：
1986-02-01
影响因子：
11.1
通讯作者：
RAICHLE, ME
中科院分区：
文献类型：
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作者：
FOX, PT;RAICHLE, ME
利用多次连续给予的¹⁵O标记放射性示踪剂（半衰期为123秒）和正电子发射断层扫描技术研究了脑血流量（CBF）和脑氧代谢率（CMRO₂）之间的耦合关系。在静息状态下，对33名正常受试者每人的多个（30 - 48个）脑区的CBF和CMRO₂进行配对测量时，发现CBF和CMRO₂之间具有极好的相关性（平均相关系数r为0.87）。然而，在躯体感觉刺激诱导的神经元激活过程中，发现CBF和CMRO₂存在区域解耦。当对9名受试者每人分别进行静息状态和刺激状态测量时，刺激诱导的脑血流量局灶性增加（平均29%）远远超过了伴随的组织代谢率局部增加（平均5%）。刺激持续时间对反应幅度或所观察到的CBF - CMRO₂解耦程度没有显著影响。推测存在一种依赖于神经元放电本身但与脑氧代谢率无关的机制（神经元或生化机制）对脑血流量进行动态的生理调节。
Coupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) was studied using multiple sequential administrations of 15O-labeled radiotracers (half-life, 123 sec) and positron emission tomography. In the resting state an excellent correlation (mean r, 0.87) between CBF and CMRO2 was found when paired measurements of CBF and CMRO2 from multpile (30-48) brain regions were tested in each of 33 normal subjects. Regional uncoupling of CBF and CMRO2 was found, however, during neuronal activation induced by somatosensory stimulation. Stimulus-induced focal augmentation of cerebral blood flow (29% mean) far exceeded the concomitant local increase in tissue metabolic rate (mean, 5%), when resting-state and stimulated-state measurements were obtained in each of 9 subjects. Stimulus duration had no significant effect on response magnitude or on the degree of CBF-CMRO2 uncoupling observed. Dynamic, physiological regulation of CBF by a mechanism (neuronal or biochemical) dependent on muronal firing per se, but independent of the cerebral metabolic rate of oxygen, is hypothesized.