Roland P E, Eriksson L, Stone-Elander S, Widen L
J Neurosci. 1987 Aug;7(8):2373-89.
Previous studies have shown that sensory stimulation and voluntary motor activity increase regional cerebral glucose consumption and regional cerebral blood flow (rCBF). The present study had 3 purposes: (1) to examine whether pure mental activity changed the oxidative metabolism of the brain and, if so, (2) to examine which anatomical structures were participating in the mental activity; and to examine whether there was any coupling of the rCBF to the physiological changes in the regional cerebral oxidative metabolism (rCMRO2). With a positron-emission tomograph (PET), we measured the rCMRO2, rCBF, and regional cerebral blood volume (rCBV) in independent sessions lasting 100 sec each. A dynamic method was used for the measurement of rCMRO2. The rCMRO2, rCBF, and rCBV were measured in 2 different states in 10 young, healthy volunteers: at rest and when visually imagining a specific route in familiar surroundings. The rCBF at rest was linearly correlated to the rCMRO2: rCBF (in ml/100 gm/min) = 11.4 rCMRO2 + 11.9. The specific mental visual imagery increased the rCMRO2 in 25 cortical fields, ranging in size from 2 to 10 cm3, located in homotypical cortex. Active fields were located in the superior and lateral prefrontal cortex and the frontal eye fields. The strongest increase of rCMRO2 appeared in the posterior superior lateral parietal cortex and the posterior superior medial parietal cortex in precuneus. Subcortically, the rCMRO2 increased in neostriatum and posterior thalamus. These focal metabolic increases were so strong that the CMRO2 of the whole brain increased by 10%. The rCBF increased proportionally in these active fields and structures, such that d(rCBF) in ml/100 gm/min = 11.1 d(rCMRO2). Thus, a dynamic coupling of the rCBF to the rCMRO2 was observed during the physiological increase in neural metabolism. On the basis of previous functional activation studies and our knowledge of anatomical connections in man and other primates, the posterior medial and lateral parietal cortices were classified as remote visual-association areas participating in the generation of visual images of spatial scenes from memory, and the posterior thalamus was assumed to participate in the retrieval of such memories.
先前的研究表明,感觉刺激和自主运动活动会增加局部脑葡萄糖消耗和局部脑血流量(rCBF)。本研究有3个目的:(1)检验单纯的思维活动是否会改变大脑的氧化代谢,如果会改变,(2)检验哪些解剖结构参与了思维活动;以及检验rCBF与局部脑氧化代谢(rCMRO2)的生理变化之间是否存在耦合。使用正电子发射断层扫描仪(PET),我们在每次持续100秒的独立时段中测量了rCMRO2、rCBF和局部脑血容量(rCBV)。采用动态方法测量rCMRO2。在10名年轻健康志愿者中,于两种不同状态下测量了rCMRO2、rCBF和rCBV:休息时以及在脑海中想象熟悉环境中的特定路线时。休息时的rCBF与rCMRO2呈线性相关:rCBF(单位:ml/100 gm/min)= 11.4 rCMRO2 + 11.9。特定的思维视觉意象使25个皮质区域的rCMRO2增加,这些区域大小从2立方厘米到10立方厘米不等,位于同型皮质。活跃区域位于额上回外侧、额中回外侧以及额眼区。rCMRO2增加最明显的区域出现在顶叶后上外侧皮质和楔前叶的顶叶后上内侧皮质。在皮质下,新纹状体和丘脑后部的rCMRO2增加。这些局部代谢增加非常显著,以至于全脑的CMRO2增加了10%。在这些活跃区域和结构中,rCBF按比例增加,使得d(rCBF)(单位:ml/100 gm/min)= 11.1 d(rCMRO2)。因此,在神经代谢的生理性增加过程中,观察到了rCBF与rCMRO2之间的动态耦合。基于先前的功能激活研究以及我们对人类和其他灵长类动物解剖学连接的了解,顶叶后内侧和外侧皮质被归类为参与从记忆中生成空间场景视觉图像的远距视觉联合区域,并且假定丘脑后部参与此类记忆的检索。