基础医学与临床 ›› 2009, Vol. 29 ›› Issue (3): 264-267.

• 研究论文 • 上一篇    下一篇

大电导钾通道对小鼠皮层神经元胞内游离钙和动作电位的影响

杨文华 白祥军 赵鸿   

  1. 华中科技大学同济医学院附属同济医院 华中科技大学同济医学院附属同济医院
  • 收稿日期:2008-02-13 修回日期:2008-06-24 出版日期:2009-03-25 发布日期:2009-03-25
  • 通讯作者: 赵鸿

Effect of BK Channels on Intracellular Free Calcium and Action Potential of Murine Cortical Neurons

Wen-hua YANG, Xiang-jun BAI, Hong ZHAO   

  1. Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
  • Received:2008-02-13 Revised:2008-06-24 Online:2009-03-25 Published:2009-03-25
  • Contact: Hong ZHAO

摘要: 目的 探讨大电导钾通道(BK)对小鼠大脑皮层神经元胞内游离钙 ( [Ca2+]i) 和兴奋性的调节作用。方法 体外培养小鼠皮层神经元,用膜片钳技术观察BK特异性阻断剂IBERIOTOXIN对神经元 [Ca2+]i和动作电位频率的影响,用显微荧光测钙法观察IBERIOTOXIN对高钾条件下[Ca2+]i的影响。结果 生理状态下,IBERIOTOXIN灌流(100nmmol/L)对神经元细胞自发动作电位的频率、[Ca2+]i无显著影响;持续电刺激去极化后,IBERIOTOXIN灌流使动作电位频率增加,[Ca2+]i显著升高。高钾溶液(20mmol/L)引起神经元[Ca2+]i升高, 而IBERIOTOXIN灌流则使[Ca2+]i进一步显著升高。结论 BK对小鼠受持续去极化刺激或高钾条件时的神经元[Ca2+]i和兴奋性具有明显调节作用。

关键词: 大电导钙激活钾通道, 神经元, 钙, 膜片钳

Abstract: Objective To investigate the role of large conductance calcium-activited potassium channels(BK) in the regulation of intracelullar free calcium concentration([Ca2+]i) and. excitability of mouse cortical neuron Methods Culture neuronal cells of C57BL/6 mouse cortex. Observe the influence of IBERIOTOXIN(100nmmol/L) on neuronal action potentials and [Ca2+]i with patch-clamp techniques. evoke prolonged depolarization of cultured neurons by 100pA electric current lasting 500ms, Measure the rate of firing and [Ca2+]i. Perfuse extracellular solution with KCl(20mmol/L), compare the changes of [Ca2+]i with or without IBERIOTOXIN (100nmol/L). Results No significant changes of neuronal spontaneous action potential frequency and [Ca2+]i was observed in physiological condition after perfusion of IBERIOTOXIN (n=7,P>0.05). The frequency of action potential evoked by electric current is higher after perfusion of IBERIOTOXIN, as well as the [Ca2+]i level during depolarization(n=9,P<0.05). Extracellular high concentration of KCl increases [Ca2+]i of neurons. When IBERIOTOXIN was applied, [Ca2+]i was much higher than without IBERIOTOXIN (n=9,P<0.05). Conclusions BK may play an important part in the regulation of neuronal intracellular free calcium and excitability.

Key words: Large conductance calcium-activited cotassium channel, Neuron, Calcium, Membrane patch-clamp