目的记录耳鸣大鼠模型听觉皮层神经元电活动,进一步探讨水杨酸钠诱导耳鸣大鼠的皮层电生理改变模式。方法将30只Wistar大鼠随机分为水杨酸钠耳鸣模型组(20只)和生理盐水组(10只)。首先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(350mg/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。并采用玻璃微电极单细胞内方式记录听觉皮层神经元的电生理变化。结果经过5天的条件反射训练,所有动物均建立了稳定的条件反射。在条件反射消退期,水杨酸钠耳鸣模型组动物条件反射的消退时间延长(P〈0.05)。水杨酸钠耳鸣模型组动物的皮层电生理有大约1/3的听觉皮质神经元对声音刺激表现为持续性反应,有1/3的神经元表现为阵发性反应,另有1/3的神经元表现为间歇性反应。结论水杨酸钠诱导耳鸣大鼠听觉皮层中的持续性反应神经元与耳鸣发生可能有直接关系。
Objective To study the electrical activity of neurons in auditory cortex of rat model of tinnitus,and further explore the electrophysiology mode of rats with tinnitus induced by sodium salicylate.Methods Adult Wistar rats(n=30)were divided randomly into two groups,normal saline group(n=10)and sodium salicylate group(n=20).First all rats were given behavioral training,and auditory identification conditioned reflex was established,then sodium salicylate(350mg/kg)was injected into the abdomen to induce and establish animal model of tinnitus.By behavioral ways we detected the emerging and dispearing of tinnitus,and then recorded the electrophysiology by the technology of glass microelectrode into single cell.Results 5 days after the conditioned reflex training,stable conditioned reflex was established in all rats.In the extinction period of the conditioned reflex,extinction time of conditioned reflex prolonged in the sodium salicylate group than in normal control(P〈0.05).The electrophysiology result of sodium salicylate group showed that one third auditory cortex neurons expressed sustained response,one third paroxysmal response,one third intermittent response.Conclusion The neurons with sustained response in auditory cortex of rats induced by sodium salicylate might be related directly to the occurance of tinnitus.