镁对海马神经元钙激活钾通道的作用

The effects of magnisium ions on Ca^(2+)-activated potassium channels in rat hippocampal neurons

目的 研究Mg2 +对海马神经元钙激活钾通道的作用 ,以揭示Mg2 +抗缺血性脑损伤的机制。方法 应用膜片钳制技术inside-out方式记录原代培养的海马神经元单通道电流活动 ,经p -CLAMP软件进行微机采样储存数据和数据分析处理。结果 Mg2 +在一定浓度范围内对海马神经元钙激活钾通道具有明显激活作用 ,增加通道开放概率 (Po) ,缩短通道关闭时间。结论 Mg2 +对海马神经元钙激活钾通道的激活作用可能为Mg2 +抗缺血性脑损伤的重要机制之一。

Objective Effects of Mg 2+ on Ca 2+ -activated potassium channels in cultured newborn rat hippocampal neurons were studied to reveal the electrophysiological mechanism about the effects of Mg 2+ on the neurons of cerebral ischemia.Methods Inside-out method of patch clamp technique was used to record the activity of single channel, configurational application of p-CLAMP software for data sampling storing and analysing. Results After magnesium ions was applied to the cytoplasmic face of the channels, activation of Mg 2+ on Ca 2+ -activated potassium channels was found. It increased dose-dependently their open probability and shortened the closed time of the channels. Conclusion Mg 2+ may protect the neurons by activating the Ca 2+ -activated potassium channels.