Proper brain function requires a substantial energy supply, up to 20% of whole-body energy in humans, and brain activation produces large dynamic variations in energy demand. While local increases in cerebral blood flow are well known, the cellular responses to energy demand are controversial. During brain excitation, glycolysis of glucose to lactate temporarily exceeds the rate of mitochondrial fuel oxidation; although the increased energy demand occurs mainly within neurons, some have suggested this glycolysis occurs mainly in astrocytes, which then shuttle lactate to neurons as their primary fuel. Using metabolic biosensors in acute hippocampal slices and brains of awake mice, we find that neuronal metabolic responses to stimulation do not depend on astrocytic stimulation by glutamate release, nor do they require neuronal uptake of lactate; instead they reflect increased direct glucose consumption by neurons. Neuronal glycolysis temporarily outstrips oxidative metabolism, and provides a rapid response to increased energy demand.

中文翻译：

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神经元刺激触发神经元糖酵解，而不是乳酸摄取。

正确的大脑功能需要大量的能量供应，最多占人体全身能量的20％，并且大脑的激活会产生巨大的动态能量需求变化。虽然脑血流量的局部增加是众所周知的，但是细胞对能量需求的反应是有争议的。在大脑兴奋过程中，葡萄糖到乳酸的糖酵解作用暂时超过了线粒体燃料的氧化速度；尽管增加的能量需求主要发生在神经元内，但有人认为这种糖酵解主要发生在星形胶质细胞中，然后星形胶质细胞将乳酸转运到神经元。在清醒小鼠的急性海马切片和大脑中使用代谢生物传感器，我们发现神经元对刺激的代谢反应不依赖于谷氨酸释放引起的星形胶质细胞刺激，也不需要神经元摄取乳酸。相反，它们反映了神经元增加的直接葡萄糖消耗。神经元糖酵解暂时超过了氧化代谢，并提供了对增加的能量需求的快速响应。