大鼠单侧耳蜗损毁对耳蜗核中γ-氨基丁酸能神经元的影响

Distribution of gama-aminobutyric acid (GABA)ergic neurons in rats cochlear nuclei after unilateral cochlea ablation

目的:研究大鼠单侧耳蜗损毁前后耳蜗核中γ-氨基丁酸(GABA)能阳性神经元的分布及数量。方法:应用免疫组织化学方法(SP法)行耳蜗核中GABA能阳性神经元分布的检测。结果:耳蜗核中GABA能神经元的体积较小、数量较多、着色很深。单侧耳蜗毁损后耳蜗核中GABA能阳性神经元的数量:术后1～2周术侧明显低于对侧(均P<0.01);术后3周上升,但仍低于对侧(P<0.05);术后1个月,术侧略低于对侧,但差异无统计学意义(P>0.05)。结论:单侧耳蜗损毁前后,GABA能阳性神经元的分布及数量在耳蜗核中呈一明显的动态变化过程,说明GABA能神经元参与了耳蜗毁损后初级听觉中枢的可塑性变化或功能重组的过程,提示GABA能神经元数量的增减可能为初级听觉中枢的重组所必需。

Objective:To observe the distribution of gama-aminobutyric acid (GABA) ergic neurons in rats cochlear nuclei(CN) in pre-and post-operation of unilateral cochlea ablation.Method:The technique of direct anti-GABA immunocytochemistry (SP) was used in this study.Result:The GABAergic neurons existed extensively in cochlear nuclei(CN). The number was more, the volume was larger of GABAergic cells in CN and those cells were stained heavily before ablation. The number of GABAergic cells in lesion side was far less than that in intact side after unilateral cochlea ablation one to two weeks(P<0.01), then the number of GABAergic cells increased after three weeks which was still less(P>0.05) and almost reached normal after a month(P>0.05).Conclusion:Thechanges of GABAergic neurons reflect the balance between excitatory and inhibitory of neurons.It suggests that changes in the extent of GABAergic inhibition have been shown to contribute to the reorganization of primary auditory central system after unilateral cochlea ablation in rats.The decrease and increase of the number of GABAergicneurons are essential for this recorganization.