GluR2/3在不同周龄大鼠耳蜗核中的表达

The Expression of GluR2/3 in Cochlear Nucleus of Different Age SD Rat

目的检测α-氨基羟甲基恶唑丙酸(α-amino-3-hydroxy-5-methyl-4-isoxazole-propionicacid,AMPA)受体亚型GluR2/3在不同周龄大鼠耳蜗核的表达及其与听性脑干反应(auditorybrainstemresponse,ABR)的关系,为听觉中枢发育的分子机制提供可能的实验依据。方法分别测定1、4、9、15周龄SD大鼠ABR反应阈;FITC标记免疫组织化学方法检测GluR2/3亚型在不同周龄SD大鼠耳蜗核中的表达。结果1周龄SD大鼠未引出明显的ABR波形,4周起能引出稳定的ABR波形,且4、9、15周龄SD大鼠ABR反应阈无显著性差异。GluR2/3在不同周龄大鼠蜗核神经元中均有表达。1周龄SD大鼠背侧蜗核(dorsalcochlearnucleus,DCN)中神经元表达较少,位于胞膜,较弱。4周龄时表达强,主要位于胞膜;9周龄时较弱,位于胞膜及胞浆;15周龄时可见于胞膜及核周胞质,但胞质较强,胞膜含量低。4周龄与1、9、15周龄胞膜相比,有显著性差异;1周龄与9、15周龄胞膜比较无显著性差异。结论出生后GluR2/3在耳蜗核的含量及分布部位均随年龄变化而变化,这种改变可能与耳蜗核的发育相关。

Objective To investigate the expression of α - amino- 3 - hydroxy - 5 - methyl - 4 - isoxazole - propionie acid（AMPA） receptor subunit proteins GluR2/3 in the postnatal rat cochlear nueleus（CN）, and the relationship with the auditory brainstem response（ABR）. Methods The thresholds of ABR of different age SD rats were recorded respectively,and the expression of GluR2/3 in CN was detected with FITC - immunocytochemistry. Results ① Plw SD rats did not show ABR wave, and there was no significant difference in the ABR threshold among P4w, P9w and P15w SD rats. ②GluR2/3 was expressed in all sorts of neurons of CN of every postnatal, groups, the expression of P4w rats was denser than that of Plw, P9w and P15w rats. The immunostairting of P4w rats was located at the cell membrance, while P9w and P15w rats in the endochylema majoritily. Conclsion The different expression and distribution of GluR2/3 in different age rat CN may be involved in the development of auditory centre.