外周听觉活性改变诱导在体听皮层突触NMDA受体表达变化

The Changes of Peripheric Auditory Activity Induced the Expression of Synaptic NMDA Receptors in Auditory cortex in Vivo

目的 观察听觉剥夺和耳蜗电刺激对听皮质突触N -甲基 -D -天冬氨酸受体 (N -methyl-D -as partatereceptor,NMDAR)表达的影响。方法 经两次不连续梯度超速离心 ,从初级听皮质提取高度纯化的突触体后 ,采用Westernblotting对耳毒性聋组、听力正常组及电耳蜗内刺激 0 .5～ 2h的各实验组听皮质突触体NMDAR三个亚型的表达进行比较。结果 证实了听觉剥夺的成年或发育期大鼠耳蜗电刺激仅仅 1.5小时可以诱导突触体NR2A蛋白的显著增加 ,但NR1和NR 2B蛋白量的改变并不显著。

Objective To study the changes of N-methyl-D-aspartate receptors(NMDARs) expression at local sy-(napses) in auditory cortices after ototoxic deafened and following electrical intracochear stimulation(EIS).Methods We prepared highly purified synaptosomes from primary auditory cortex by two discontinuous gradient centrifugations, and compared the differences of NMDA receptors expression in ototoxic deafened group control group, normal control group and different experimental groups (EIS from 0.5h to 2h ) by Western blotting.Results We found that EIS for as little as half and one hour the adult and developmental rats of auditory deprivation can induce a significant increase in NMDAR subunit2A (NR2A) protein. But the changes of NMDAR subunit1(NR1) and NMDAR subunit2B(NR2B) are not significant.Conclusion There is a rapid activity-dependent expression of synaptic NR2A receptors in primary auditory cortex in vivo.