听觉剥夺和耳蜗内电刺激引起幼鼠听觉通路bdnf和c-fos基因及蛋白改变  

Variations of bdnf and c-fos and their proteins in the auditory pathway induced by auditory deprivation and intracochlear electrical stimulation in infant rats

作　　者：卢振东[1] 杨军[2,3] 

机构地区：[1]新疆石河子大学医学院,新疆石河子832000 [2]上海交通大学医学院附属新华医院耳鼻咽喉-头颈外科 [3]上海交通大学医学院耳科学研究所,上海200092

出　　处：《山东大学耳鼻喉眼学报》2012年第3期17-23,共7页Journal of Otolaryngology and Ophthalmology of Shandong University

基　　金：上海市科委医学引导项目(114119a6300)

摘　　要：目的观察耳聋幼鼠及耳聋后单耳植入电极电刺激后,其听皮层和下丘、耳蜗核三个部位的脑源性神经营养因子(brain-derived neurotrophic factor,bdnf)、c-fos基因、蛋白表达水平的变化情况。方法将66只SD幼鼠随机分为6组,每组11只,分别为注射药物后耳聋4周组(A1组)及对照组(A2组),耳聋6周组(B1组)和及对照组(B2组),注射药物后3周接受耳蜗内电刺激组(C组),5周接受耳蜗内电刺激组(刺激时间为1周,D组)。于幼鼠颈背部、两侧下腹部皮下注射庆大霉素(总量为350 mg/kg),0.5 h后于相同部位注射呋塞米(总量为200 mg/kg)。分别于注射药物后不同时间取听皮层、下丘及耳蜗核三个部位的组织行实时荧光定量PCR及免疫组织化学方法,观察bdnf及c-fos基因及蛋白表达的变化。结果 A1组在听皮层、下丘及耳蜗核部位的bdnf及c-fos基因及蛋白表达均较A2组上升,较C组下降(P<0.05)。B1组在听皮层、下丘及耳蜗核部位bdnf及c-fos基因及蛋白表达均较B2组和D组下降(P<0.05)。各组之间的差异均有统计学意义。结论听觉剥夺可导致幼鼠听皮层、下丘和耳蜗核部位的bdnf及c-fos基因及蛋白早期表达增多,而晚期表达下降。耳蜗植入电极电刺激可导致幼鼠听皮层、下丘和耳蜗核部位的bdnf及c-fos基因及蛋白表达增多。bdnf及c-fos基因及蛋白表达的动态变化反映三个部位的可塑性变化。Objective To observe variations of the brain-derived neurotrophic factor （bdnf） and c-fos and their pro- teins induced by auditory deprivation and intracochlear electrical stimulation in the auditory cortex, inferior colliculus and cochlear nucleus in infant rats. Methods Sixty-six SD infant rats were randomly divided into 6 groups：the 4- week group（ group A1 ）, the 6-week group （ group B1 ） with injection of ototoxic drug and their homologus control group（ group A2 ,B2）, the 3-week group（ group C）, and the 5-week group（ group D） with injection of ototoxic drug with intracochlear electrical stimulation for one week. Each group consisted of 11 rats. Gentamicin sulphate （350 mg/kg body weight） and frusemide （200 mg/kg body weight） were subcutaneously injected in the skin folds on the lateral abdominal side and the dorsal neck area. Expressions of mRNAs and proteins encoded by bdnf and c-fos were detected by real-time PCR and immunohistological staining. Results Real-time PCR and immunohistochemistry re-vealed that expressions of mRNAs and proteins encoded by bdnf and c-fos significantly increased in group A1 as com- pared to group A2, and decreased as compared to group C （ P 〈 0.05 ）, in the auditory cortex, inferior colliculus and cochlear nucleus. However, expressions of them significantly decreased in the group B1 as compared to group B2 and group D （ P 〈 0.05 ）. Conclusion Auditory deprivation results in expressions of mRNAs and proteins encoded by bdnf and c-fos increas in early stage and decreasing in the later stage in auditory cortex, inferior colliculus and cochlear nu- cleus. Intracochlear electrical stimulation makes expression of them increase in rats with auditory deprivation. The dy- namic variations of bdnf and c-fos and their proteins reflected the plasticity in neurons of the auditory pathway.

关 键 词：听觉可塑性 脑源性神经营养因子(bdnf) c—fos 电刺激 感音神经性聋 

分 类 号：R764.43[医药卫生—耳鼻咽喉科]