Epileptiform ictal discharges are prevented by periodic interictal spiking in the olfactory cortex
Epileptiform ictal discharges are prevented by periodic interictal spiking in the olfactory cortex
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DOI：
10.1002/ana.10471
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发表时间：
2003-03-01
影响因子：
11.2
通讯作者：
de Curtis, M
中科院分区：
文献类型：
--
作者：
Librizzi, L;de Curtis, M
在人类癫痫发作和动物癫痫模型中，通常观察到间期电位。不确定部分癫痫发作间峰是否与发作时放电有因果关系。为了分析发作间期和发作期癫痫样事件之间的相互关系，我们对离体豚鼠脑制剂的边缘系统进行了细胞外记录。体外动脉灌注双库兰（50muM）持续诱导海马-内嗅区局灶性尖峰放电，在三分之一的实验中，这种放电与梨状皮质周期性的间期尖峰有关。在没有活跃的间歇尖峰时，梨状皮质会被海马-内嗅区发起的突发放电继发侵入，而在大约0.1至0.2Hz的周期性梨状皮质尖峰存在时，没有观察到继发的突发夹带。同样，在动脉灌注二胡兰之前，在梨状皮质局部注射同样的药物，也不会发生突发事件，这一过程会诱发持续的间歇尖峰。在梨状皮质的两次间歇峰之间，观察到海马对传入的阵发性放电的反应性降低。
Interictal potentials are commonly observed between seizures in human epilepsies and in animal models of epilepsy. It is uncertain whether interictal spiking in partial epilepsies is causally related with the onset of an ictal discharge. To analyze the reciprocal correlation between interictal and ictal epileptiform events, we performed extracellular recordings in the limbic system of the in vitro isolated guinea pig brain preparation. Arterial perfusion of bicuculline (50muM) in vitro consistently induced a focal ictal discharge in the hippocampal-entorhinal region that in one third of the experiments was associated with periodic interictal spikes in the piriform cortex. In the absence of active interictal spiking, the piriform cortex was secondarily invaded by the ictal discharge initiated in the hippocampal-entorhinal region, whereas no secondary ictal entrainment was observed in the presence of periodic piriform cortex spikes at circa 0.1 to 0.2Hz. Similarly, ictal events never occurred when arterial perfusion of bicuculline was preceded by a local injection of the same drug in the piriform cortex, a procedure that induces a sustained interictal spiking. A reduced responsiveness to incoming paroxysmal discharges generated in the hippocampus was observed during the interval between two interictal spikes in the piriform cortex.