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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 observe the changes of N-methyl-D-aspartate (NMDA) receptor subunit NR2A in auditory cortex synapses in auditory remodeling after sound insulation. Methods: Forty-five SD rats were divided into three groups: sound insulation group, acoustic remodeling group and control group, 15 rats each. Optiprep sedimentation gradient ultracentrifugation was used to extract highly purified synaptosome from primary auditory cortex. blotting Western blotting was used to detect the expression of NR2A in cortical synaptosomes of experimental groups exposed to pure tone for 14 days, 28 days, 42 days, and 7 days after sound insulation. Results: After the sound insulation, NR2A expression in the auditory cortex of 14d and 28d after birth was significantly decreased (P <0.05), and after 7d of sound insulation, the NR2A expression was significantly increased (P <0.05) Adjust the trend. Sound insulation and pure tone exposure had no significant effect on the expression of NR2A in the auditory cortex of mature rats42d after birth (P> 0.05). Conclusion: Auditory experience can change the expression of NMDA receptor NR2A in the auditory cortex at the critical stage of development in rats. The results provide important experimental data for studying the mechanism of plasticity of sensory function.