中文摘要：

目的：通过向细胞内微量注射IP3受体激动剂诱发细胞内高钙,探讨细胞内高钙对小鼠小脑浦肯野细胞内在电生理特性变化的影响。方法：取小鼠小脑蚓部做矢状切片（400μm）。采用Axoclamp-2B放大器全细胞记录模式,记录细胞内Ca2＋浓度升高前后浦肯野细胞动作电位的阈电位和绝对不应期 电信号输入pClamp9.2软件获取和分析群集发放的动作电位峰间距和动作电位峰时程标准差,进行数据采集和分析,观察细胞内Ca2＋浓度升高早期浦肯野细胞内在电生理特性的变化。结果：细胞内Ca2＋浓度升高后的短时间内,与高钙前相比,小脑浦肯野细胞群集发放动作电位的不应期缩短和激发动作电位的阈电位降低（P〈0.001）。结论：细胞内高钙改变动作电位的不应期和阈电位,使浦肯野细胞兴奋增加,动作电位的编码能力降低。

英文摘要：

Objective：To study the changes of the intrinsic electrophysiological characteristics of cerebellar Purkinje cells during the stage of the elevation of intracellular Ca2＋ through micro-injected of IP3 receptor excitomotor of Purkinje cells in cerebellar vermis. Methods：The sagittal slices of cerebellar vermis （400 μm） were prepared. The recordings of threshold potential of firing spike and absolute refractory period following each spike of cytoplasmic Ca2＋ elevation cells were conducted in whole-cell model with an Axoclamp-2B amplifier;and electrical signals were inputted into pClamp 9.2 for data acquisition and analysis of inter-spike interval and standard deviation of spike timing. The changes in the intrinsic electrophysiological properties at Purkinje neurons during the elevation of intracellular Ca2＋ were examined. Results：Shortly after the elevation of intracellular Ca2＋ , compared with before, refractory period of sequential spikes was shorten, the threshold potential of firing spikes was lower（P 〈 0. 001 ）. Conclusions ：The elevation of cytoplasmic Ca2. alters the refractory period and threshold potential of sequential spikes,leads to increase of the excitability and deteriorated spike encoding of cerebellar Purkinje cells.