无镁诱导海马神经元癫痫样放电中Cx32作用的研究

目的:探讨缝隙连接在癫痫发病机制中的作用。方法:采用无镁液诱导的体外原代培养新生大鼠海马神经元细胞癫痫模型,应用膜片钳技术记录细胞外放电。观察放电不同时点缝隙连接蛋白Cx32的表达情况,以及生胃酮和卡马西平的抑制作用。结果:神经元经无镁培养液处理3h后产生稳定的放电,放电后Cx32表达显著增多,8h后可达对照组5倍。生胃酮和卡马西平均可抑制神经元的放电。生胃酮显著抑制了Cx32的表达,而卡马西平组Cx32水平无明显变化。结论:缝隙连接参与癫痫的发生发展过程,而且具有独立于传统的化学性突触的机制,为开发新的作用于缝隙连接的治疗药物提供了思路。

Involvement of connexin 32 in epileptiform discharges induced by zero-Mg2+ in cultured hippocampal neurons in rat

Objective: To study the role of gap junction in epileptiform activity induced by zero-Mg2 in cultured hippocampal neurons in rats.Methods: The epileptiform activity following zero-Mg2 medium in cultured neurons for 3 hours was recorded with whole-cell patch clamp recording techniques.Besides the expression of Cx32 protein of neurons at different time after discharging,the inhibition by carbenoxolone and carbamazepine was determined.Results: During the zero-Mg2 medium exposure,regular seizure-like discharges developed at 3 hours in neurons.The expression level of Cx32 protein began to develop at 2 hours after restoration to normal medium and was raised by five times at 8 hours compared to the results from the control group.Both carbenoxolone and carbamazepine could inhibit the interictal-like activity,however only carbenoxolone depressed the expression of Cx32 to the level in control group and carbamazepine showed little effect on Cx32.Conclusions: Gap junction contributes to epileptiform activity with different mechanisms with the traditional chemical synapse,suggesting a direction for the development of new drugs targeting gap junctions for therapeutic intervention.