中文摘要：

目的研究SD大鼠视网膜双极细胞（RBCs）L-钙通道电流的特点。方法选取11只4～8周龄SD大鼠制备视网膜切片标本,RBCs胞体位于视网膜内核层最外部,以辨别细胞。使用全细胞膜片钳的方法,记录视网膜RBCs的L-钙通道电流。结果在显微镜下从切片上识别位于视网膜内核层最外部的RBCs胞体。用玻璃毛细管微电极在RBCs胞体记录出L-钙通道电流,慢电容补偿：（3.2±0.3）pF,阶越（step）刺激的电流峰值：（31.1±3.3）pA,斜坡（ramp）刺激的电流峰值：（32.5±3.1）pA;使用L-钙通道阻断剂nifedipine可以成功阻断电流。结论实验中记录出的电流为L-钙通道电流。使用全细胞膜片钳的方法在大鼠视网膜切片上记录RBCs的L-钙通道电流是可行的。

英文摘要：

Objective It has been shown previously that L-type calcium current play a pivotal role in transmitter release of rod bipolar cells.To understand the characterastics of L-type calcium currents in retinal bipolar cells of normal SD rats is very important for the study of rats with congenital stationary night blindness and retinal cone degeneration.The purpose of this study was to explore the features of L-type calcium currents in retinal bipolar cells of normal SD rats.Methods The eyeballs were extracted from 11 4-to 8-week-old SD rats and the 150 μm retinal slices were prepared.The rod bipolar cell bodies were searched under the microscope.L-type calcium currents in rod bipolar cells were recorded using whole cell patch clamp technique by glass capillary microelectrod.Results The some of retinal bipolar cells could be identified in the outermost part of the inner nuclear layer（INL）in the slices using microscope.The parameters of recorded L-type calcium currents were as follows：slow capacitance：3.2±0.3 pF,peak amplitude of the voltage-step recordings：31.1±3.3 pA and the value of the voltage-ramp recordings：32.5±3.1pA.The currents could be blocken by nifedipine.Conclusion L-type calcium currents in the rod bipolar cells can be recorded using the whole cell patch clamp technique in the retinal slices.