发育期大鼠视皮层锥体神经元自发兴奋性突触后电流变化  

Changes of spontaneous EPSCs in visual cortex neurons of rat during development period

作　　者：张卫鹏[1,2] 史学峰[1,2] 邢咏新[1,2] 赵堪兴[1,2] 

机构地区：[1]天津医科大学眼科临床学院眼肌科,天津300020 [2]天津市眼科医院

出　　处：《天津医科大学学报》2009年第2期169-172,183,共5页Journal of Tianjin Medical University

基　　金：国家自然科学基金资助项目(30730099)

摘　　要：目的：研究发育过程中大鼠视皮层2／3层锥体神经元的白发兴奋性突触后电流（sEPSCs）变化，以及在生后早期自发性突触活动情况，探讨视觉经验在视皮层发育过程中对神经元突触的修饰作用。方法：应用红外微分干涉相差显微镜（m—DIC）结合电荷耦合式摄像机（CCD—Camera）可视法膜片钳全细胞记录生后2—7、8～14、15-21、22-28d各组sEPSCs变化。同时于电极内液中加入虫荧光黄，对所记录细胞进行染色观察形态学改变。结景：视皮层神经元sEPSCs幅值随发育逐渐升高（单因素方差分析P〈0．01）。视皮层神经元sEPSCs频率随发育逐渐提高（单因素方差分析P〈0．01）。但2～7d组与8—14d组差异无统计学意义（两独立样本t检验P〉0．05）。视皮层2，3层神经元胞体及突起以及生物电学特性随发育逐渐成熟。结论：大鼠视皮层锥体神经元突触后膜AMPA受体功能表达随发育逐渐成熟，生后早期突触并非完全处于静息状态，具有一定的早期白发突触功能活动。Objective： To investigate the modificational function of visual experience onto synapses by recording developmental changes of spontaneous EPSCs in layer 2/3 pyramidal neurons of rat visual cortex, and observe the spontaneous synaptic activities during the earlier postnatal period. Methods： By combining infrared differential interference contrast （IR-DIC） technique and CCD-Camera system with visual patch clamp whole-cell recording technique, spontaneous EPSCs of P2-7,P8-14,P15-21,P22-28 groups were oberved and analyzed,simultaneously the neurons were stained by adding luciferyellow to the pipette solution. Results： The amplitude of sEPSCs was enhanced when aging （one way ANOVA, P〈0.01）.The sEPSCs frequency increased with age （one way ANOVA, P〈0.01）.There was no significant difference between P2-7 group and P8-14 group （two independent sample t-test, P〉0.05）. The electrophysiology and dendrite of neuron became mature over development. Conclusion： Although most synapses are regarded as silent synapses at early postnatal days,which show exclusively NMDA receptor-mediated function,the results imply there are early AMPA receptor-mediated functional activities in layer 2/3 pyramidal neurons,synapses are not completely silent, they do have early spontaneous activities.

关 键 词：视皮层 突触发育 静息突触 自发性兴奋性突触后电流 AMPA受体 

分 类 号：R339.146[医药卫生—人体生理学] R777.44[医药卫生—基础医学]