Scaling of brain metabolism with a fixed energy budget per neuron: implications for neuronal activity, plasticity and evolution.
Scaling of brain metabolism with a fixed energy budget per neuron: implications for neuronal activity, plasticity and evolution.
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DOI：
10.1371/journal.pone.0017514
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发表时间：
2011-03-01
期刊：
影响因子：
3.7
通讯作者：
Herculano-Houzel S
中科院分区：
文献类型：
--
作者：
Herculano-Houzel S
通常认为，较大的大脑具有较大的神经元，这些神经元单独消耗更多的能量，因此每个神经元伴随着大量的神经胶质细胞。然而，这些概念从未被验证过。基于清醒动物的葡萄糖和氧代谢率及其最近确定的神经元数量，在这里，我表明，与预期相反，每个神经元的估计葡萄糖使用量非常恒定，在六种啮齿动物和灵长类动物（包括人类）中仅变化40%。估计的每个神经元的平均葡萄糖使用与任何结构中的神经元密度都不相关。这表明，每个神经元的整个大脑的能量预算在物种和大脑大小之间是固定的，因此整个大脑、大脑皮层和小脑单独使用的总葡萄糖是整个物种结构中神经元数量的线性函数（尽管大脑皮层中每个神经元的平均葡萄糖消耗至少比小脑高10倍）。这些结果表明，在人类中，仅占身体质量2%的大脑明显地使用了全身能量预算的20%，这仅仅是因为它有大量的神经元。由于突触活动被认为是代谢成本的主要决定因素，因此每个神经元的保守能量预算对突触稳态和放电率的调节、突触可塑性、脑成像、病理学以及进化中的脑缩放具有几个深远的影响。
It is usually considered that larger brains have larger neurons, which consume more energy individually, and are therefore accompanied by a larger number of glial cells per neuron. These notions, however, have never been tested. Based on glucose and oxygen metabolic rates in awake animals and their recently determined numbers of neurons, here I show that, contrary to the expected, the estimated glucose use per neuron is remarkably constant, varying only by 40% across the six species of rodents and primates (including humans). The estimated average glucose use per neuron does not correlate with neuronal density in any structure. This suggests that the energy budget of the whole brain per neuron is fixed across species and brain sizes, such that total glucose use by the brain as a whole, by the cerebral cortex and also by the cerebellum alone are linear functions of the number of neurons in the structures across the species (although the average glucose consumption per neuron is at least 10× higher in the cerebral cortex than in the cerebellum). These results indicate that the apparently remarkable use in humans of 20% of the whole body energy budget by a brain that represents only 2% of body mass is explained simply by its large number of neurons. Because synaptic activity is considered the major determinant of metabolic cost, a conserved energy budget per neuron has several profound implications for synaptic homeostasis and the regulation of firing rates, synaptic plasticity, brain imaging, pathologies, and for brain scaling in evolution.
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DOI：
10.1126/science.1166673
发表时间：
2009-04-03
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Gilestro GF;Tononi G;Cirelli C
通讯作者：
Cirelli C
影响因子：
2.5
作者：
Azevedo, Frederico A. C.;Carvalho, Ludmila R. B.;Herculano-Houzel, Suzana
通讯作者：
Herculano-Houzel, Suzana
DOI：
10.1073/pnas.83.4.1140
发表时间：
1986-02-01
影响因子：
11.1
作者：
FOX, PT;RAICHLE, ME
通讯作者：
RAICHLE, ME
影响因子：
2.9
作者：
Herculano-Houzel S
通讯作者：
Herculano-Houzel S
影响因子：
4.1
作者：
Grossman, LI;Schmidt, TR;Goodman, M
通讯作者：
Goodman, M