Department of Psychology and Program in Developmental Neuroscience, College of Staten Island, City University of New York, Staten Island, New York 10314, United States.
Epilepsy Res. 2011 Nov;97(1-2):92-102. doi: 10.1016/j.eplepsyres.2011.07.008. Epub 2011 Aug 30.
Rat hippocampal area CA3 pyramidal cells synchronously discharge in rhythmic bursts of action potentials after acute disinhibition or convulsant treatment in vitro. These burst discharges resemble epileptiform activity, and are of interest because they may shed light on mechanisms underlying limbic seizures. However, few studies have examined CA3 burst discharges in an animal model of epilepsy, because a period of prolonged, severe seizures (status epilepticus) is often used to induce the epileptic state, which can lead to extensive neuronal loss in CA3. Therefore, the severity of pilocarpine-induced status epilepticus was decreased with anticonvulsant treatment to reduce damage. Rhythmic burst discharges were recorded in the majority of slices from these animals, between two weeks and nine months after status epilepticus. The incidence and amplitude of bursts progressively increased with time after status, even after spontaneous behavioral seizures had begun. The results suggest that modifying the pilocarpine models of temporal lobe epilepsy to reduce neuronal loss leads to robust network synchronization in area CA3. The finding that these bursts increase long after spontaneous behavioral seizures begin supports previous arguments that temporal lobe epilepsy exhibits progressive pathophysiology.
在急性去抑制或致惊厥处理后，体外培养的大鼠海马 CA3 锥体神经元会同步发放具有节律性的动作电位簇。这些簇放电类似于癫痫样放电，这很有趣，因为它们可能为边缘性癫痫发作的机制提供线索。然而，由于癫痫持续状态（status epilepticus）常被用来诱导癫痫状态，这会导致 CA3 中广泛的神经元丢失，因此在癫痫动物模型中很少研究 CA3 簇放电。因此，用抗惊厥药物治疗来降低 pilocarpine 诱导的癫痫持续状态的严重程度，以减少损伤。在癫痫持续状态后两周至九个月，这些动物的大多数切片中都记录到了节律性簇放电。即使在自发行为性癫痫发作开始后，簇放电的发生率和幅度仍随时间逐渐增加。这些结果表明，通过修饰颞叶癫痫的 pilocarpine 模型以减少神经元丢失，会导致 CA3 中强大的网络同步。这些簇放电在自发行为性癫痫发作开始后很长时间仍增加的发现，支持了先前关于颞叶癫痫具有进行性病理生理学的观点。
