隔声后听觉重塑模型中听皮质突触NR2A表达的变化  

Expression of NR2A in rat auditory cortex after sound insulation and auditory plasticity

作　　者：夏寅[1] 龙海珊[1] 韩德民[1] 龚树生[1] 雷厉[1] 史金凤[1] 范尔仲[2] 李颖[2] 赵庆[3] 

机构地区：[1]首都医科大学附属北京同仁医院耳鼻咽喉头颈外科耳鼻咽喉头颈科学教育部重点实验室(首都医科大学),北京100730 [2]北京市耳鼻咽喉科研究所 [3]中国医学科学院基础研究所

出　　处：《临床耳鼻咽喉头颈外科杂志》2009年第11期508-512,共5页Journal of Clinical Otorhinolaryngology Head And Neck Surgery

基　　金：国家"十五"科技攻关项目(No:2004BA720A18-02);北京市自然科学基金(重点项目)资助项目(No:7031001;7212008);首都医学发展科研基金资助项目(No:2003-1013)

摘　　要：目的:观察隔声后听觉重塑模型中听皮质突触N-甲基-D-天冬氨酸(NMDA)受体亚基NR2A表达的变化。方法:采用清洁级SD大鼠45只,分成隔声组、隔声后听觉重塑组及对照组各15只,Optiprep沉降梯度超速离心从初级听皮质提取高度纯化的突触体后,采用Western blotting蛋白质印迹检测技术对生后隔声14d组、28d组、42d组、隔声7d后再给予纯音暴露的各实验组听皮质突触体NR2A表达进行比较。结果:隔声使生后14d组和28d组动物听皮层NR2A表达水平明显下降(P<0.05),隔声7d后再给予纯音暴露则又使NR2A表达水平明显提高(P<0.05),呈现双向调节趋势。隔声和纯音暴露对生后42d组成熟大鼠听皮层NR2A表达不再产生明显调节作用(P>0.05)。结论:在大鼠生后发育关键期,听觉经验可改变听皮层NMDA受体NR2A蛋白表达水平。研究结果为研究感觉功能发育可塑性的机制提供了重要的实验资料。Objective：To study the changes of N-methyl-D-aspartate（NMDA） receptor subunit 2A （NR2A） expression at local synapses in auditory cortices after early postnatal sound insulation and tone exposure. Method.. We prepared highly purified synaptosomes from primary auditory cortex by Optiprep floatation gradient centrifugations, and compared the differences of NR2A expression in sound insulation PND14, PND28, PND42 and Tone exposure after sound insulation for 7 days by Western blotting. Result： The results showed that the NR2A protein expression of PND14 and PND28 decreased significantly（P〈0.05）. Tone exposure after sound insulation for 7 days, mSIe NR2A protein level increased significantly（P〈0.05）. It showed bidirectional regulation of NR2A protein. No significant effects of sound insulation and lone exposure were found on the relative expression level of NR2A of PND42（P〉0.05）. Conclusion： The results indicate that sound insulation and experience can modify the protein expression level of NR2A during the critical period of rat postnatal development. These findings provid important data for the study on the mechanisms of the developmental plasticity of sensory functions.

关 键 词：突触体 初级听皮层 NMDA受体 突触的可塑性 隔声 

分 类 号：R339.16[医药卫生—人体生理学]