Sheth Sameer, Nemoto Masahito, Guiou Michael, Walker Melissa, Pouratian Nader, Toga Arthur W
Laboratory of NeuroImaging, Department of Neurology, University of California, Los Angeles, School of Medicine, Los Angeles, CA 90024, USA.
Neuroimage. 2003 Jul;19(3):884-94. doi: 10.1016/s1053-8119(03)00086-7.
We investigated the coupling between perfusion-related brain imaging signals and evoked neuronal activity using optical imaging of intrinsic signals (OIS) at 570 and 610 nm. OIS at 570 nm reflects changes in cerebral blood volume (CBV), and the 610 nm response is related to hemoglobin oxygenation changes. We assessed the degree to which these components of the hemodynamic response were coupled to neuronal activity in rat barrel, hindpaw, and forepaw somatosensory cortex by simultaneously recording extracellular evoked field potentials (EPs) and OIS while varying stimulation frequency. In all stimulation paradigms, 10 Hz stimulation evoked the largest optical and electrophysiological responses. Across all animals, the 610 late phase and 570 responses correlated linearly with sigmaEP (P < 0.05) during both whisker deflection and electrical hindpaw stimulation, but the 610 early phase did not (whisker P = 0.27, hindpaw P = 0.28). The signal-to-noise ratio (SNR) of the 610 early phase (whisker 3.1, hindpaw 5.3) was much less than that for the late phase (whisker 14, hindpaw 51) and 570 response (whisker 11, hindpaw 46). During forepaw stimulation, however, the 610 early phase had a SNR (17) higher than that during hindpaw stimulation and correlated well with neuronal activity (P < 0.05). We conclude that the early deoxygenation change does not correlate consistently with neuronal activity, possibly because of its low SNR. The robust CBV-related response, however, has a high SNR and correlates well with evoked cortical activity.
我们使用570和610纳米的内在信号光学成像（OIS）研究了灌注相关脑成像信号与诱发神经元活动之间的耦合。570纳米的OIS反映脑血容量（CBV）的变化，而610纳米的反应与血红蛋白氧合变化有关。我们通过在改变刺激频率的同时记录细胞外诱发场电位（EPs）和OIS，评估了大鼠桶状、后爪和前爪体感皮层中这些血流动力学反应成分与神经元活动的耦合程度。在所有刺激模式中，10赫兹刺激诱发的光学和电生理反应最大。在所有动物中，在触须偏转和电刺激后爪期间，610纳米的晚期反应和570纳米的反应与σEP呈线性相关（P < 0.05），但610纳米的早期反应不相关（触须P = 0.27，后爪P = 0.28）。610纳米早期反应的信噪比（SNR）（触须3.1，后爪5.3）远低于晚期反应（触须14，后爪51）和570纳米反应（触须11，后爪46）。然而，在前爪刺激期间，610纳米的早期反应的SNR（17）高于后爪刺激期间，并且与神经元活动相关性良好（P < 0.05）。我们得出结论，早期脱氧变化与神经元活动并非始终相关，可能是因为其SNR较低。然而，与CBV相关的强烈反应具有高SNR并且与诱发的皮层活动相关性良好。
