羟丁酸钠对海马神经细胞钙激活钾通道的作用

The Effect of Sodium Gammahydroxybutyrate on Hippocampal Neuronal Calciumactivated Potassium

应用膜片钳技术研究了羟丁酸钠对海马神经元中电导钙激活钾通道的作用。实验选用培养３～７天的锥体神经元，在对称性高钾溶液中，应用细胞贴附式膜片和内面向外式膜片记录通道电流。结果发现：（１）该通道电导为６５ｐＳ左右，对胞内〔Ｃａ２＋〕１敏感，特异钾通道阻断剂（ＴＥＡ）能抑制或阻断该通道活动；（２）在细胞贴附式膜片上，羟丁酸钠明显增加该通道的开放概率。因此，羟丁酸钠对海马神经细胞中电导钙激活钾通道具有明显的激活作用。

The purpose of this research was to study the effect of sodium gammahydroxybutyrate on the middle conductance Calciumactivated potassium(IK)channel in the culture of hippocampal neurons of newbon rat.All the experiments were carried out on 3～7 days old neurons.Single channel current signals were recorded in symmetrical high potassium was solution under cellattached patch and insideout parch.The results showed that:(1) In insideout patch,the unitary conductance was 65+12pS.The IK channel activity was activated by internal calcium was but was blocked by potassium channel blocker(TEA).(2)In cellattached patch,when sodium gammahydroxybutyrate was added into the bath solution,the open probability(Po)was markedly increased(P<005),where as there was no change in amplitude(P>005)。So the sodium gammahydroxybutyrate activate the IK channel of hippocampal neurons.