大剂量苯巴比妥对惊厥幼鼠浦肯野细胞电生理功能的影响

 目的：研究单次大剂量苯巴比妥对惊厥幼鼠小脑浦肯野细胞(Purkinje cells, PCs)电生理功能的影响。方法：将健康新生7 d (P7) SD幼鼠随机分为正常对照组、惊厥模型组和苯巴比妥组。给予幼鼠腹腔注射戊四氮60 mg/kg制作惊厥模型。苯巴比妥按120 mg/kg一次性腹腔注射。采用全细胞膜片钳记录法在小脑脑片上记录小脑PCs动作电位及PCs兴奋性突触后电流（excitatory postsynaptic current, EPSC）的长时程抑制（long-term depression, LTD）。结果：（1）苯巴比妥组幼鼠小脑PCs诱发动作电位的阈值降低,频率增高。（2）苯巴比妥组幼鼠小脑PCs EPSC幅值在低频刺激后15 min内降低的幅度显著大于其它2组。结论:单次大剂量苯巴比妥增加了惊厥幼鼠小脑PCs的兴奋性,并改变了小脑PCs的突触功能。

Effect of high-dose phenobarbital on electrophysiological characteristics of Purkinje cells in neonatal rats with seizures

AIM：To investigate the effect of single high-dose phenobarbital (PB) on the electrophysiological characteristics of cerebellar Purkinje cells (PCs) in neonatal rats with seizures. METHODS：Seven-day-old Sprague-Dawley neonatal rats were randomly divided into control group, seizure group and PB group. Seizures were induced by pentetrazole (60 mg/kg, ip), and PB (120 mg/kg, ip) was applied to neonatal rats in PB group. The evoked action potential and excitatory postsynaptic current (EPSC) long-term depression (LTD) of the PCs were recorded by the technique of whole-cell patch clamp on the cerebellar slices. RESULTS：PB decreased the threshold of action potential in the PCs and increased the fire rate. During the first 15 min after stimulation, LTD was induced, and the inhibition of EPSC of the PCs was enhanced significantly by PB. CONCLUSION:Single high-dose PB increases the excitability of PCs and changes the synaptic functions of cerebellar PCs in the neonatal rats with seizures.