Raichle Marcus E, Mintun Mark A
Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Annu Rev Neurosci. 2006;29:449-76. doi: 10.1146/annurev.neuro.29.051605.112819.
Functional brain imaging with positron emission tomography and magnetic resonance imaging has been used extensively to map regional changes in brain activity. The signal used by both techniques is based on changes in local circulation and metabolism (brain work). Our understanding of the cell biology of these changes has progressed greatly in the past decade. New insights have emerged on the role of astrocytes in signal transduction as has an appreciation of the unique contribution of aerobic glycolysis to brain energy metabolism. Likewise our understanding of the neurophysiologic processes responsible for imaging signals has progressed from an assumption that spiking activity (output) of neurons is most relevant to one focused on their input. Finally, neuroimaging, with its unique metabolic perspective, has alerted us to the ongoing and costly intrinsic activity within brain systems that most likely represents the largest fraction of the brain's functional activity.
正电子发射断层扫描和磁共振成像等功能性脑成像技术已被广泛用于绘制大脑活动的区域变化。这两种技术所使用的信号都基于局部循环和代谢（大脑活动）的变化。在过去十年中，我们对这些变化的细胞生物学的理解有了很大进展。关于星形胶质细胞在信号转导中的作用以及对有氧糖酵解对脑能量代谢的独特贡献的认识都有了新的见解。同样，我们对负责成像信号的神经生理过程的理解也从认为神经元的放电活动（输出）最相关，发展到专注于它们的输入。最后，神经成像以其独特的代谢视角，使我们意识到大脑系统中持续且代价高昂的内在活动，这很可能代表了大脑功能活动的最大部分。
