培养大鼠海马胆囊收缩素阳性神经元的电生理学特性

目的 探索海马内胆囊收缩素(CCK) 阳性（CCK⁺ ）神经元的电生理学特性。方法 用整合有CCK启动子-绿色荧光蛋白(GFP)的腺病毒对培养海马CCK⁺神经元进行标记，应用全细胞膜片钳技术对标记CCK⁺神经元的电生理学特性进行研究。结果 CCK⁺神经元的胞体长径为(22.85±0.77)μm，短径为(16.21±0.42)μm (n=20)，静息电位 (RMP)为(-55.90±1.30)mV，膜电容 (Cm)为(45.77±2.06)pF，膜阻抗 (Rm)为(711.00±46.69)MΩ； CCK+神经元500 ms内100 pA去极化电流诱发动作电位的发生频率为(26.17±3.41)Hz (n=12)； CCK⁺神经元的自发抑制性突触后电流的发生频率［(5.26±0.71)Hz, n=7］显著高于自发兴奋性突触后电流的发生频率［(3.24±0.62)Hz, n=6］。 结论 CCK⁺神经元的相关电生理学特征可能与其在中枢神经系统内重要的调节功能相关。

Electrophysiological characteristics of cultured hippocampal cholecystokinin positive neurons

Objective To explore the electrophysiological properties of cultured hippocampal cholecystokinin (CCK) positive (CCK⁺ ) neurons. Methods The cultured hippocampal CCK⁺ neurons were labeled by an adenovirus encoding CCK promoter and green fluorescent protein (GFP) and then whole cell patch clamp technique was carried on to explore the electrophysiology characteristic of hippocampal CCK⁺ neurons. Results The long diameter of CCK⁺ neurons’cell body was (22.85±0.77)μm, and the short diameter was (16.21±0.42)μm. The membrane electrophysiology parameters of CCK⁺ neurons were as following.
Rest membrane potential was(-55.90±1.30)mV. Membrane capacity was (45.77±2.06)pF. Membrane resistance was (711.00±46.69)MΩ. The action potential firing frequency of cultured hippocampal CCK⁺ neurons was (26.17±3.41)Hz. The spontaneous inhibitory postsynaptic currents frequency of CCK⁺ neurons was (5.26±0.71)Hz, which was significant higher compared to the frequency of spontaneous excitatory postsynaptic currents ［(3.24±0.62)Hz］. Conclusion The electrophysiology characteristics of hippocampal CCK⁺ neuron may be colsely related to its modulatory effect in central nervous system.