The cause of the imbalance in the neuronal network leading to seizure activity can be predicted by the electrographic pattern of the seizure onset.
The cause of the imbalance in the neuronal network leading to seizure activity can be predicted by the electrographic pattern of the seizure onset.
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DOI：
10.1523/jneurosci.5309-08.2009
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发表时间：
2009-03-18
期刊：
影响因子：
--
通讯作者：
Engel J Jr
中科院分区：
文献类型：
--
作者：
Bragin A;Azizyan A;Almajano J;Engel J Jr
本研究探讨了GABAA受体拮抗剂荷包牡丹碱和谷氨酸激动剂红藻氨酸注射到海马CA 3区引起的发作性电活动的时间动力学。实验在自由活动的成年Wistar大鼠中进行，在多个脑区植入微电极。记录宽带电活动（0.1-3000 Hz），并研究每种药物的癫痫发作潜伏期以及电活动模式。从注射到第一次癫痫样事件发生的间隔时间，荷包牡丹碱为3.93 ± 2.76（±STD）min，红藻氨酸为6.37 ± 7.66 min，提示脑内存在强大的癫痫抑制机制。荷包牡丹碱在注射部位诱发高振幅节律性癫痫样事件，类似于发作间期EEG棘波，并迅速传播到邻近和远端脑区。红藻氨酸诱发了一个完全不同的模式，在30-80 Hz的活动幅度逐渐增加。虽然有很强的时间相关性的EEG事件在该网站的荷包牡丹碱注射和放电在远处的地区，少得多的相关性与红藻氨酸注射。这两种模式之后，普遍发作脑电图放电和行为癫痫发作。我们的研究结果表明，大脑的同一区域可以触发不同的电图模式的癫痫发作。这两种不同的电图模式的网络机制的知识可能有助于设计预防癫痫发作的差异化策略。
This study investigates the temporal dynamics of ictal electrical activity induced by injection of the GABAA receptor antagonist bicuculline, and the glutamate agonist kainic acid, into the CA3 area of hippocampus. Experiments were conducted in freely moving adult Wistar rats implanted with microelectrodes in multiple brain areas. Wide-band electrical activity (0.1–3000 Hz) was recorded, and the latency of seizure onset as well as the pattern of electrical activity were investigated for each drug. The latencies between injection and the occurrence of first epileptiform events were 3.93 ± 2.76 (±STD) min for bicuculline and 6.37 ± 7.66 min for kainic acid, suggesting the existence of powerful seizure-suppressive mechanisms in the brain. Bicuculline evoked high-amplitude rhythmic epileptiform events at the site of injection which resembled interictal EEG spikes and rapidly propagated to adjacent and remote brain areas. Kainic acid evoked a completely different pattern with a gradual increase in the amplitude of 30–80 Hz activity. Whereas there was strong temporal correlation between EEG events at the site of bicuculline injection and discharges in distant areas, much less correlation was seen with kainic acid injection. Both patterns were followed by generalized ictal EEG discharges and behavioral seizures. Our results illustrate that the same area of the brain can trigger seizures with different electrographic patterns. The knowledge of the network mechanisms underlying these two distinct electrographic patterns might be helpful in designing differential strategies for preventing seizure occurrence.