吗啡对前额叶皮层神经元突触释放的荧光显像研究

Effect of Morphine on Synaptic vesicle release in Cultured Prefrontal Cortex Neurons

目的将探讨吗啡能否影响突触前神经递质囊泡的释放过程。方法研究采用FM1-43(苯乙烯类染料)标记培养的前额叶皮层神经元突触前囊泡,应用高钾溶液使神经元去极化从而导致突触囊泡释放。通过记录FM1-43荧光减少的过程来分析吗啡对突触前囊泡释放动力学曲线的影响。在细胞灌流液中分别加入吗啡或纳洛酮来分别模拟成瘾和戒断状态。结果 FM1-43可以直观的显示神经元囊泡的释放情况;细胞外高钾可以诱导囊泡的释放,且有剂量依赖性;在培养的前额叶皮层神经元,吗啡单独处理或吗啡和纳洛酮合并使用后不同时间(1、3、5、10天)对高钾刺激诱导的囊泡释放的动力学曲线都没有明显影响。结论 FM1-43标记神经元是一种可靠的研究突触释放的方法,但在培养的额叶皮层神经元,吗啡未能改变高钾诱导的突触囊泡释放,同样用naloxone模拟急性戒断也不会对囊泡释放的动力学产生影响。提示在研究吗啡成瘾过程中造成的神经功能改变的机制时,需要更加全面深入的机制研究。

Objective To explore the effect of morphine on the release of presynaptic neurotransmitter vesicles.Methods FM1-43(styrene dye)was used to labelthe presynaptic vesicles in cultured neurons derived from prefrontal cortex and,high potassium solution to induce synaptic vesicle release vianeuronal membrane depolarization.The effect of morphine on the release kinetics of presynaptic vesicles was analyzed by recording the decrease of FM1-43fluorescence.Morphine or naloxone was added into the bath solution to mimicthe morphine addiction and withdrawal status,respectively.Results FM1-43faithfully displayed the neuronal vesicular release and high extracellular potassium induced vesicle release in a dose dependent manner.However,morphine or morphine plus naloxone treatment for135,and10days had no influence on vesicle release kinetics in cultured prefrontal cortex neurons stimulated by90mM potassium.Conclusion There sults demonstrated the validity of applying FM1-43to monitorvesicle release of cultured prefrontal cortex neurons.The negative results of morphine on the vesicle release necessiated the combination of FM1-43and other techniques in exploring the mechanisms for morphine-induced neuronal dysfunctions involved in addiction.