水杨酸钠对小鼠下丘核神经元GABAα、NR1表达及听反应的影响

THE EFFECTS OF SODIUM SALICYLATE ON THE EXPRESSION OF GABAα,NR1 AND HEARING RESPONSE PROPERTIES OF INFERIOR COLLICULUS NEURONS IN MICE

目的:探讨水杨酸钠给药对小鼠下丘核神经元GABAα、NR1表达及听反应的影响。方法:实验将36只成年健康昆明小鼠分三组(n=12):A组:对照组;B组:水杨酸钠给药组(450mg.kg-1.d-1);C组:水杨酸钠(450mg.kg-1.d-1)+利多卡因(10mg.kg-1.d-1)组。各组均经腹腔注射给药,A组给以同等剂量的生理盐水,所有动物自由饮食。给药15 d后进行检测。采用RT-PCR技术检测小鼠下丘核区GABAα、NR1mRNA的表达;采用细胞外电生理记录技术研究下丘核区神经元在水杨酸钠给药后强度-发放率函数、强度-潜伏期函数和频率调谐曲线的变化。结果:①水杨酸钠组的下丘核区GABAαmRNA表达较对照组明显降低(P<0.05);水杨酸钠+利多卡因组与对照组比较无显著性差异(P>0.05);水杨酸钠组NR1mRNA表达较对照组明显升高(P<0.01),水杨酸钠+利多卡因组与对照组比较有显著性差异(P<0.05);②水杨酸钠给药后发放率和潜伏期函数呈非单调性改变,而神经元的调谐曲线从狭窄型向宽阔型转变;③水杨酸钠+利多卡因组发放率和潜伏期函数呈非单调性改变,而神经元的调谐曲线从狭窄型向宽阔型转变例数显著减少(P<0.05,P<0.01)。结论:①水杨酸钠引起实验小鼠下丘核GABAαmRNA表达下调,同时又使小鼠下丘核NR1mRNA表达增高;②水杨酸钠给药后发放率和潜伏期函数呈非单调性改变,而神经元的调谐曲线从狭窄型向宽阔型转变③利多卡因有逆转水杨酸钠给药后发放率和潜伏期函数呈非单调性改变和神经元的调谐曲线从狭窄型向宽阔型转变的作用。

Aim： To study the effects of sodium salicylate on the expression of GABAα NR1 and hearing response properties of inferior colliculus neurons in mice. Methods： Thirty-six kunming mice were divided into three groups（A,B,C, ）. The expression of GABAα NR1 were measured by using RT-PCR. The intensity-rates functions, intensity-latency functions and frequency-turning curves were recor ded by extracellular electrophysiological recording techniques. Results： ①The expression of GABAα mRNA of B group was decreased remarkably than the control group（A group, P 〈 0.05）, there weren＇t noticeable differences between A group and C group （P 〉 0.05）. The expression of NRlmRNA of B group was increased remarkably than the control group（A group, P 〈 0.01 ）, there were noticeable differences between A group and C group （P 〈 0.05）. ② The intensity-rates functions , intensity-latency functions were monotonic while the frequency-turning curves were more broad when sodium salicylate was given.③The intensity-rates functions, intenslty-latency functions were non-monotonic while the frequency-turning curves were sharpened after lidocaine was given. Conclusions ：①The results suggested that administration of sodium salicylate decreased the expression of GABAα while increased the expression of NRlmRNA. ②The intensity-rates functions, intensity-latency functions were monotonic,the frequency-turning curves were more broad when salicylate was given and the changes above could be reversed by given lidocaine.