Attwell David, Iadecola Costantino
Dept of Physiology, University College London, Gower Street, UK.
Trends Neurosci. 2002 Dec;25(12):621-5. doi: 10.1016/s0166-2236(02)02264-6.
The haemodynamic responses to neural activity that underlie the blood-oxygen-level-dependent (BOLD) signal used in functional magnetic resonance imaging (fMRI) of the brain are often assumed to be driven by energy use, particularly in presynaptic terminals or glia. However, recent work has suggested that most brain energy is used to power postsynaptic currents and action potentials rather than presynaptic or glial activity and, furthermore, that haemodynamic responses are driven by neurotransmitter-related signalling and not directly by the local energy needs of the brain. A firm understanding of the BOLD response will require investigation to be focussed on the neural signalling mechanisms controlling blood flow rather than on the locus of energy use.
血流动力学对神经活动的反应是功能磁共振成像（fMRI）中用于大脑的血氧水平依赖（BOLD）信号的基础，人们通常认为这种反应是由能量消耗驱动的，尤其是在突触前终末或神经胶质细胞中。然而，最近的研究表明，大脑中的大部分能量用于为突触后电流和动作电位提供动力，而非突触前或神经胶质细胞的活动，此外，血流动力学反应是由神经递质相关信号驱动的，而不是直接由大脑的局部能量需求驱动的。要对BOLD反应有一个确切的理解，需要将研究重点放在控制血流的神经信号机制上，而不是能量使用的位点上。
