青霉素致（癎）大鼠海马细胞内Ca2＋浓度变化与神经元单位放电的关系

Study on the relationship between changes in Ca2＋ concentration and unit discharge in the hippocampal neurons of rats with benzylpenicillin-induced epilepsy

目的 探讨癫（癎）大鼠海马细胞内Ca2＋浓度变化和神经元单位放电的关系.方法36只Wistar雄性健康大鼠分为3组.癫（癎）模型组用青霉素钠600万U/kg腹腔注射制作成癫（癎）模型;癫（癎）预处理组在制作模型前用盐酸氟桂利嗪按20 mg/kg间隔12 h灌胃2次,第2次给药后2 h用青霉素钠600万U/kg腹腔注射制作模型.3组实验大鼠均在记录单位放电后处死,取双侧海马应用新一代钙荧光指示剂Fluo-3-AM通过流式细胞分析仪测定细胞内Ca2＋荧光浓度.结果 正常对照组大鼠共记录到24个单位海马神经元放电,海马细胞内Ca2＋平均荧光浓度为37.12±5.08;癫（癎）模型组共记录到78个单位海马神经元放电,海马细胞内Ca2＋平均荧光浓度为52.04±6.75;癫（癎）预处理组共记录到47个单位海马神经元放电,海马细胞内Ca2＋平均荧光浓度为37.79±3.09.Ca2＋平均荧光值和海马单位放电个数相关系数r=0.737,P＜0.01.结论 青霉素致病大鼠海马细胞内Ca2＋浓度变化与海马神经元单位放电呈正相关关系.

Objective To investigate the relationship between changes in Ca2＋ concentration and unit discharge in the hippocampal neurons of epileptic rats.Methods Thirty-six healthy male Wistar rats were divided into three groups. Rats of the epilepsy group received an intraperitoneal injection of benzylpenicllin sodium at 6 million unit/kg; Rats of the epilepsy pretreatment group received 20 mg/kg of flunarizine at 14 and 2 hours before injection of benzylponicllin;the control group of rats received an intraperitoneal injection of normal saline.Three groups of rats were euthanized after recording of the unit discharge,and bilateral hippocampal cells were obtained to measure the cellular concentration of Ca2＋ fluorescence using the new generation Ca2＋ fluorescent dye Fluo-3-AM and flow cytometry.Results （1） A total of 24 units of hippocampal discharges were recorded in the control group.The average concentration Ca2＋ fluorescence of the hippocampal neurons was 37.12±5.08.（2）A total of 78 units of hippocampal discharges were recorded in the epilepsy group.The average concentration of Ca2＋fluorescence of the hippocampal neurons was 52.04±6.75.（3）A total of 47 units of hippocampal discharges were recorded in the epilepsy pretreatment group. The average concentration of Ca2＋ fluorescence of the hippocampal neurons was 37.79±3.09.The correlation coefficient between the average concentration of Ca2＋ fluorescence of the hippocampal neurons and the number of units of hippocampal discharge （ r=0.737,P〈0.01）.Conclusion There is a positive correlation between changes in average concentration of Ca2＋ fluorescence of the hippocampal neurons and the numbers of units of hippocampal discharge.