吗啡慢性处理对大鼠前额叶皮层神经元瞬时外向钾电流的影响

THE EFFECTS OF CHRONIC MORPHINE TREATMENT ON TRANSIENT OUTWARD K^+ CURRENT OF NEWBORN RAT CORTICAL NEURONS

目的:本实验用全细胞膜片钳技术观察吗啡对大鼠前额叶皮层神经元瞬时外向钾电流(IA)的影响。方法:实验中用终浓度为10μmol/L的吗啡处理细胞48h,采用全细胞膜片钳技术记录IA,进行以下方面的实验:培养大鼠皮层神经元IA的特性及鉴定;吗啡对神经细胞IA的电流密度-电压曲线(Ⅰ-Ⅴ曲线)的影响。结果:记录到一快速激活并快速失活的外向电流,该电流可被2mmol/L的特异性IA阻断剂4-AP阻断;吗啡慢性处理能引起大鼠皮质神经细胞IA增强,当膜电位在-25mV～+65mV时,吗啡慢性处理组电流密度明显高于对照组。结论:吗啡能引起神经细胞IA增强,使神经元处于超极化状态,导致其活动抑制。

Objective： To observe the effects of chronic morphine treatment on the transient outward K^＋ current （IA） of newborn rat cortical neurons.Methods： Cells were treated by morphine with a final concentration of 10μmol/L.The whole-cell patch-clamp technique was used to do the following test： the characteristics and identification of IA of cultured newborn rat prefrontal cortical neurons,and the impact of morphine on I -V curve of IA. Results ：A rapid activation and inactivation outward current was recorded,which could be blocked by specific IA repressor 2mmol/L 4-AP.When the voltage range was-25 mV-＋65 mV, there was significantly increased current density in morphine group.Conclusion： Chronic morphine treatment can increase IA current density of newborn rat cortical neurons,making the neurons in its hyperpolarization state, and inhibit the activity of the neurons.