μ-和δ-阿片受体对神经元树突棘可塑性调节的动态观察

Dynamic observe that μand δ opiate receptor modulate the plasticity of dendritic spines

目的探讨μ阿片（MOR）和δ阿片受体（DOR）在海马神经元树突棘可塑性调节中的功能角色。方法用磷酸钙共沉淀法将编码绿色荧光蛋白EGFP的质粒转染到5-9D IV原代培养海马神经元,EGFP标记的神经元发育到2周时,随机挑选形态健康的神经元作为观察目标,使用倒置荧光显微镜对同一视野活细胞定时定位观察MOR受体促进剂吗啡和DOR受体促进剂DPDPE给药前及给药后3 h、24 h、72h树突棘形态大小及密度变化。结果1.吗啡组和吗啡＋DPDPE组,从形态学观察,部分树突棘在给药后24-72h内逐渐变小,甚至消失;2.吗啡组加药后3 h树突棘的密度无明显变化（P〉0.05）,24 h后降低了28%,72 h后降低了37%（P〈0.01）;吗啡＋DPDPE组加药后3 h树突棘的密度无明显变化（P〉0.05）,24h后降低了27%（P〈0.05）,72 h后降低了38%（P〈0.01）;DPDPE组和对照组在给药后3-72 h树突棘的密度无明显变化（P〉0.05）;而DPDPE单独给药组和对照组神经元树突棘形态大小、密度在各时间点均无明显变化。结论本实验表明阿片MOR受体参与了神经元树突棘可塑性的调节,动摇了树突棘的稳定性,而DOR受体无显著作用,同时MOR和DOR受体在对神经元可塑性调节方面也无协同作用。

Objective To investigate the functional roles of μ opiate receptors（MOR） and δ opiate receptors （DOR） in synaptic plasticity. Methods Hippocampal neuronal culture were prepared from rats at postnatal 1 -2 days, Hippocampal neurons （5-9DIV） were transfected plasmid encoding EGFP using the calcium phosphate coprecipitation method with some modification, the culture dish fit tightly in a holding chamber on a fixed platform above an inverted fluorescence microscopy sitting on an X-Y translation stage. The location of any neuron of interest was determined by reading of the X-Y translation stage. Neurons could be found again in the next observation using the X-Y translation stage. The first images were taken in a EGFP-labeled neuron at the age of 2 weeks after plating. Morphine and DPDPE were immediately applied to the culture medium, and same dendritic spines were photographed again at various times （3h, 24h, 72h）. Results The density of dendritic spines were decreased by 28 % after 24 h （ P 〈 0.05 ） and 37 % after 72 h （ P 〈 0.01 ） in morphine treatment group. It also significantly decreased the density of spines by 27% after 24 h （ P 〈 0.05 ） and by 38% after 72h （ P 〈 0.01 ） in morphine ＋ DPDPE group. The density of dendritic spines were not significantly changed in untreated control neuron and DPDPE treated alone group in 3 days. The size of dendrite spines were decreases, some of spines eventually disappearing after 3 days treatment in both of morphine group and morphine ＋ DPDPE group. Conclusion MORs participate in modulating the plasticity of dendrites spines. It seems that DORs doesnt play crucial regulation roles in plasticity of dendrites spines. MORs and DORs don＇ t interact with each other in regulating the plasticity of dendrites spines.