中文摘要：

目的通过建立Müller细胞内谷氨酰胺合成酶损伤模型,探讨b波的时频域特征,检测谷氨酸代谢对b波时频域的影响。方法大鼠（Rcs-rdy!-p!）右眼注射4μL不同浓度（7、70、140μg/μL）的谷氨酸合成酶抑制剂（DL-AAA）,左眼注射等计量PBS作为对照组。采用RETI-scan系统,环形角膜电极和不锈钢针状电极,记录18只30 d龄大鼠系列暗适应视网膜电图。导出数据后,在Matlab7.1环境下自编程序行小波分析。行配对样本t检验统计学分析。结果时域特征：随着DLAAA浓度的增加,a、b波的幅值降低。在低浓度时双眼间无统计学差异,中、高浓度实验组a、b波幅值较对照组均明显降低（P〈0.05,P〈0.01）,而b波的峰时未见明显变化。高浓度时,b/a及T1/2d均出现明显变化。频域特征：在设定包络阈值为0.8时,归一化处理后发现,低浓度时最小环比基本重合,而随着药物浓度的增加,实验组最小环比则明显增高（P〈0.05）,且离散度增高,同时最高峰值的时间点后延（P〈0.05）。结论抑制谷氨酰胺合成酶后,视网膜内谷氨酸代谢出现异常,该变化对b波的贡献在时域上体现为早期成分,在频域上体现为慢相低频成分,且对维持视网膜功能稳定性起到重要作用。

英文摘要：

Objective To investigate the contributions of glutamate metabolism to electroretinogram（ ERG） b-wave in time and frequency domains by wavelet transform in a glutamine synthetase（ GS） inhibited rat model. Methods Different concentrations of glutamine synthetase inhibitor（ DL-AAA） were subretinally injected into the right eyes of Rcs-rdy＋-p＋rats,and phosphate buffer solution was subretinally delivered into the left eyes as control. Dark-adapted ERG of all the rats was recorded with an RETI-scan system. A gold-foil ring cornea electrode was used as the recording electrode and a home-made stainless steel needle electrode was used as the reference electrode. The intensity of light ranged from-40 d B to 5 d B. Data were collected and analyzed with software Matlab7. 0,and students ’ t test was used for statistical analysis. Results The characteristics of time domain as follows： with the increase of DL-AAA concentration,the amplitudes of a-wave and b-wave were decreased. In the low concentration group,no any significant change was observed.However,the amplitudes had significant changes in the middle and high concentration groups as compared with the control group（ P 〈 0. 05,P 〈 0. 01）. Moreover,in the high concentration group,the parameters（ b /a and T1 /2d） were changed dramatically. The characteristics of frequency domain as follows： when the envelope threshold was set at 0. 8,with the increase of DL-AAA concentration,the minimum ratio of circle increased and the dispersion increased（ P 〈 0. 05）. Meanwhile,the time of peak delayed（ P 〈 0. 05）.Conclusion The glutamate metabolism in the retina is disrupted after inhibiting GS in Müller cells,and this change contributes to the earlier part of ERG b-wave in the time domain and the slower part in the frequency domain,indicating that Müller cells play a major role in the stability of the retinal function.