GRAMFC, EA 4293, Neurophysiology Lab, Faculty of Medicine, University of Picardy, Rue des Louvels, Amiens, France.
Neuroimage. 2010 Apr 1;50(2):600-7. doi: 10.1016/j.neuroimage.2010.01.009. Epub 2010 Jan 11.
The mechanisms that drive neurons to synchronize in epileptic spikes are still subject to debate. In the present study, we used a combination of electrocorticography and near-infrared spectroscopy (ECoG/NIRS) to evaluate haemodynamic changes before, during and after epileptic spikes induced by administration of bicuculline methiodide (BM) onto the sensorimotor cortex in 8 adult Sprague-Dawley rats. Simultaneous ECoG/NIRS signals were recorded during an initial reference period (to measure spontaneous bioelectrical/metabolic activities) and then again 60 min after BM administration. Spikes in the ECoG were detected by an in-house program based on MatLab 7.0. The appearance times of the P1 peaks were used to determine corresponding time periods in the NIRS for further analysis. We observed a pronounced pre-spike modification in the haemodynamics, which became visible latest 5 s before the spike, achieving after some oscillations its minimum at round about the P1 appearance time. The post-spike period was characterized by an initial increase in oxyhaemoglobin (HbO) and total haemoglobin (HbT) to a maximum at about 2 s after the spike followed by a phase of declining oscillations disappearing after 10 to 15 s after the spike. We discuss the mechanisms underlying the haemodynamic and electrical changes that occur before, during and after epileptiform spikes. The haemodynamic changes observed with NIRS and occurring before the spikes constitute a haemodynamic predictor of electrical synchronization of spikes.
导致神经元在癫痫发作中同步的机制仍存在争议。在本研究中，我们使用脑电描记术和近红外光谱（ECoG/NIRS）相结合的方法，评估在 8 只成年 Sprague-Dawley 大鼠的感觉运动皮层上给予荷包牡丹碱甲碘化物（BM）后诱发癫痫发作期间和之后的血液动力学变化。在初始参考期（测量自发的生物电/代谢活动）期间同时记录 ECoG/NIRS 信号，然后在 BM 给药后 60 分钟再次记录。ECoG 中的尖峰由基于 MatLab 7.0 的内部程序检测。使用 P1 峰的出现时间来确定 NIRS 中的相应时间段以进行进一步分析。我们观察到血液动力学在尖峰前有明显的预尖峰修饰，最晚在尖峰前 5 秒可见，在大约 P1 出现时间达到其最小值后经历一些振荡。尖峰后期间的特征是在尖峰后约 2 秒达到最大的氧合血红蛋白（HbO）和总血红蛋白（HbT）初始增加，随后是一个下降振荡的阶段，在尖峰后 10 到 15 秒后消失。我们讨论了在癫痫样尖峰发生前后发生的血液动力学和电变化的机制。在尖峰发生之前观察到的 NIRS 血液动力学变化构成了尖峰电同步的血液动力学预测因子。
