The effect of IL-6 on the epilepticus-induced seizures in a rat model of focal cortical dysplasia

LI Chouzhong; GAO Fangyou; SUN Jie

Abstract：Objective The effects of interleukin-6 (IL-6) on the epileptic discharges of malformations of cortical development (MCD) in rats were studied by the topical delivery of drugs and the monitoring technique of multi-electrode cortical electroencephalography (EEG).Methods MCD model was established by freezing the cortex with liquid nitrogen:new-bom SD rats were subjected to local cryopreservation of cerebral cortex.After the establishment of the model,the morphology and behaviors were evaluated.One week before surgery,the MCD model mice were subjected to cortical EEG.All the rats were randomly divided into pilocarpine group and pilocarpine plus IL-6 group.Rats in the model group were injected intraperitoneally with lithium chloride (180 mg/kg),20 h later the rats were injected intraperitoneally with atropine sulfate 1 mg/kg,and 20 mg/kg piloearpine after 30 min.The model plus IL-6 group used the local injection of IL-6.Baseline monitoring was performed 30 min prior to injection and electrophysiological testing was performed immediately after the injection.After monitoring,the behavior of the animal and other related electrophysiological indicators,such as latency,duration and so on were analyzed.Results All rats in the experimental group showed blinking,rhythmic chewing and rhythmic nodding immediately after injection of pilecarpine,and they had the episode of more than Class Ⅳ after 30 min.But the action of IL-6 injection group was significantly reduced and appeared later.The electrophysiological results showed that the incubation period was significantly prolonged (31.05 ±2.35) min in the model-induced plus IL-6 injection group compared with the model induced group (25.93 ± 1.33) min.Compared with the model-induced group (34.58 ± 1.02) s,the latency period in the model-induced (17.75 ± 1.94) s was decreased significantly,and there was a significant difference between the two groups (P ＜0.01).The number of spontaneous epileptic discharges was significantly decreased (12.00 ±3.03) in model induced group plus IL-6 injected group compared with the model induced group (28.83 ±4.26).There was significant difference between two groups (P ＜0.01).Conclusion IL-6 can significantly reduce the threshold of epileptic discharge and reduce the duration of discharge,which nay have a protective effect on epileptic seizure.