[目的]检测耳鸣大鼠听觉皮层神经元NR2A的mRNA和蛋白表达,探讨其在耳鸣发生中的作用.[方法] 将20只Wistar大鼠随机分为水杨酸钠组(10只)和生理盐水组(10只).对大鼠进行行为训练,建立听觉识别条件反射,然后腹腔注射水杨酸钠(350 mg/kg)诱导建立大鼠耳鸣动物模型,通过行为学方法检测耳鸣的产生与消失.利用RT-PCR和Western-blot方法于水杨酸钠腹腔注射后d7检测听觉皮层神经元NR2A的mRNA及蛋白的表达情况.[结果] 经过5 d的条件反射训练,所有动物均建立了稳定的条件反射.在条件反射消退期,水杨酸钠组动物条件反射的消退时间延长,差异有显著性(P<0.05).水杨酸钠组大鼠听觉皮层NR2A的mRNA和蛋白的表达较生理盐水组明显升高,差异有显著性(P<0.05).[结论]耳鸣大鼠听觉皮层神经元NR2A表达的升高与耳鸣的发生相关.
[Objectivel To detect the mRNA and protein expression of NR2A on auditory cortex neurons of rats with tinnitus and explore its role in the occurrence of tinnitus. [Methodsl Adult Wistar rats( n =20) were divided randomly into normal saline group( n = 10) and sodium salicylate group( n = 10). First all rats were given behavioral training, and auditory identification conditional reflex was established, and then sodium salicylate(350mg/kg) was injected into the abdomen to induce and establish the animal model of tinnitus. Behavioral way was used to detect the emerging and disappearing of tinnitus. On the 7th day of intraperitoneal injection of sodium salicylate, the mRNA and protein expression of NR2A in auditory cortex neurons were detected by RT-PCR and Western-blot methods. [Results] After 5 days of the conditional reflex training, stable conditional reflex was established in all rats. In the extinction period, extinction time of conditional reflex prolonged in the sodium salicylate group, and the difference was significant( P 〈0.05). The mRNA and protein expression of NR2A on auditory cortex of rats in the sodium salicylate group was significantly higher than that in the saline group, and the difference was significant ( P 〈0.05). [Conelusionl NR2A expression on auditory cortex neurons in rats with tinnitus increases, which is related to the pathogenesis of tinnitus.