Devor Anna, Dunn Andrew K, Andermann Mark L, Ulbert Istvan, Boas David A, Dale Anders M
Massachusetts General Hospital NMR Center, Harvard Medical School, Charlestown, MA 02129, USA.
Neuron. 2003 Jul 17;39(2):353-9. doi: 10.1016/s0896-6273(03)00403-3.
Recent advances in brain imaging techniques, including functional magnetic resonance imaging (fMRI), offer great promise for noninvasive mapping of brain function. However, the indirect nature of the imaging signals to the underlying neural activity limits the interpretation of the resulting maps. The present report represents the first systematic study with sufficient statistical power to quantitatively characterize the relationship between changes in blood oxygen content and the neural spiking and synaptic activity. Using two-dimensional optical measurements of hemodynamic signals, simultaneous recordings of neural activity, and an event-related stimulus paradigm, we demonstrate that (1) there is a strongly nonlinear relationship between electrophysiological measures of neuronal activity and the hemodynamic response, (2) the hemodynamic response continues to grow beyond the saturation of electrical activity, and (3) the initial increase in deoxyhemoglobin that precedes an increase in blood volume is counterbalanced by an equal initial decrease in oxyhemoglobin.
包括功能磁共振成像（fMRI）在内的脑成像技术的最新进展，为脑功能的无创映射带来了巨大希望。然而，成像信号与潜在神经活动之间的间接性质限制了对所得图谱的解释。本报告是第一项具有足够统计效力的系统性研究，旨在定量表征血氧含量变化与神经放电及突触活动之间的关系。通过对血流动力学信号进行二维光学测量、同时记录神经活动以及采用事件相关刺激范式，我们证明：（1）神经元活动的电生理测量与血流动力学反应之间存在强烈的非线性关系；（2）血流动力学反应在电活动饱和后仍持续增长；（3）血容量增加之前脱氧血红蛋白的初始增加被氧合血红蛋白同等程度的初始减少所抵消。
