摘要
目的观察单侧耳蜗损毁后听皮层中抑制性神经递质γ-氨基丁酸(gamma-aminobutyric acid,GABA)和甘氨酸(glycine,Gly)含量的变化,初步探讨去传入损伤后 GABA 和 Gly 在听觉中枢可塑性改变中的作用和意义。方法健康 SD 大鼠20只随机分为4组:正常组、假手术组和单侧耳蜗损毁后1 wk、3 wk 组。于规定时间内检测耳蜗损毁前后 GABA 和 Gly 含量的水平。比较听皮层不同时间点的 GABA 和 Gly 含量。结果与假手术组相比,损毁后1 wk,听皮层中 GABA 的含量明显下降(从40.26±4.58降至27.41±3.53,约31.9%),差异有显著性(P<0.05),Gly 的含量也明显下降(从10.40±1.74降至4.92±0.40,约52.7%),差异极为显著(P<0.01);至术后3 wk,听皮层中 GABA 的含量水平明显上升但仍低于假手术组,但差异无统计学意义(P>0.05);Gly 的含量水平也呈上升趋势,但仍明显低于假手术组,且差异有极显著性(P<0.01)。结论在听皮层中 GABA 和 Gly 具有协调释放效应,提示二者在单侧耳蜗损毁后听觉中枢神经系统的可塑性改变中可能起重要作用。
Purpose To observe the changes of GABA and Gly in rat auditory cortex following unilateral cochlea damage and explore the function and significance of GABA and Gly in plasticity of auditory cortex after deafferented.Methods Twenty Sprangue Dawley(S-D)rats wre divided randomly into four groups.The content of GABA and Gly were measured by 835-50 type Amino Acid Automatism Analyzer and compared before and after operation.Results Compared with sham operated groups,one week after unilateral cochlea damage,the content levels of GABA decreased(from 40.26±4.58 to 27. 41±3.53,about 31.9%)and there was a difference in GABA levels between the two groups(P<0.05),the content levels of Gly also decreased(from 10.40±1.74 to 4.92±0.40,approximately 52.7%)and a distinctly significant difference was observed in Gly levels between two groups(P<0.01).After three weeks,the content levels of GABA increased and almost reached the normal levels,but differences had no statistically significance(P>0.05).The content levels of Gly increased also,but they were lower than that of normal,and there was a distinctly significant differenee between the two groups(P< 0.01).Conclusion The co-release effect of GABA and Gly was observed in rat auditory cortex,which implied that both GABA and Gly may play an important role in plasticity of auditory central nervous system after unilateral cochlea damage.
出处
《中国眼耳鼻喉科杂志》
2004年第6期353-355,共3页
Chinese Journal of Ophthalmology and Otorhinolaryngology
