耳鸣模型大鼠听皮层生长相关蛋白-43和细胞骨架活性调节蛋白的表达

Expression of GAP-43 and ARC in the Auditory Cortex of Rats Experiencing Tinnitus

目的检测神经元功能可塑性基因生长相关蛋白-43(growth associated protein,GAP-43)和细胞骨架活性调节蛋白(activity regulated cytoskeleton associated protein,ARC)在水杨酸诱导耳鸣大鼠听皮层中的表达,探讨其在耳鸣产生中的作用。方法将24只白色Wistar大鼠随机分为3组:水杨酸钠组(8只)、生理盐水组(8只)和空白对照组(8只)。前两组从条件反射建立前开始于每次条件反射训练前2小时分别腹腔注射10%水杨酸钠溶液(350mg/kg)和同体积生理盐水,至实验结束,空白对照组不做任何处理。通过行为学方法证实水杨酸钠组动物感受到耳鸣后,利用荧光定量PCR检测动物听皮层中GAP-43和ARC的表达。结果水杨酸钠组大鼠听皮层中GAP-43和ARC蛋白阳性神经元的表达(分别为2.17±0.72、4.90±2.13)明显高于生理盐水组(分别为1.05±0.20、1.13±0.42)和空白对照组(分别为0.96±0.97、1.07±0.70)(P<0.01),而生理盐水组和空白对照比较差异无统计学意义(P>0.05)。结论耳鸣大鼠听皮层中神经元功能可塑性基因GAP-43和ARC蛋白阳性神经元的表达增加,推测它们可能在耳鸣的发生发展中起重要作用。

Objective To investigate the expression and the possible role of GAP--43（growth associated protein,GAP--43） and ARC （activity regulated cytoskeleton associated protein, ARC） in the auditory cortex of rats which experienced tinnitus. Methods Twenty--four white Wistar rats were randomly distributed into 3 groups： sodium salieylate group（n=8）, physiological saline group（n：8） and the control group （n=8）. Tinnitus was induced by salicylate administration and evaluated by behavioral conditioning techniques, and fluorescence quantitative PCR was used to observe the expression of GAP--43 and ARC in the auditory cortex in each group. Results GAP--43 and ARC positive neurons were observed in all rats. The expression of GAP 43 and ARC in the sodium salieylate group was significantly higher than that of other two groups（P〈0.01）. Conclusion The higher expression of GAP-- 43 and ARC in the auditory cortex of rats experiencing tinnitus suggests their important roles in the mechanism of tinnitus.