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GABAA 受体抑制性通路增强视网膜神经节细胞活动的相关性

刘雪, 张莹莹, 龚海庆, 梁培基^*

上海交通大学生命科学技术学院，神经信息处理实验室，上海 200240

摘要

本文对小鸡视网膜中相邻的瞬时型神经节细胞在全域白光刺激下放电活动的相关性进行了研究。药理学实验和互相 关分析的结果显示，GABAA 受体的拮抗剂荷包牡丹碱(bicuculline, BIC)的施加可以增强细胞的放电频率，并显著地减弱细胞 间的相关性反应强度。GABAA 受体的激动剂蝇蕈醇(muscimol, MUS)在抑制细胞放电频率的同时却增强了细胞间的相关性放电 活动。然而，在GABAC 受体的拮抗剂1,2,5,6- 四氢吡啶-4- 甲基磷酸[(1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid, TPMPA]的作用下，一部分细胞的放电频率增强，而另一部分细胞的放电频率减弱；相关性反应变强或变弱的细胞对也各占 近半。这些结果提示，在小鸡视网膜中，当GABAA 受体被激活后，虽然细胞的放电频率被抑制，但相邻瞬时型神经节细 胞之间放电活动的相关性却增强。GABAA 受体介导的抑制性通路的活动可以提高视觉信息传递的效率。

关键词： 视觉; 抑制; GABAA 受体; 相关性研究

分类号：Q25

The GABAA receptor mediated inhibitory pathway increases the correlated activities in retinal ganglion cells

LIU Xue, ZHANG Ying-Ying, GONG Hai-Qing, LIANG Pei-Ji^*

Laboratory of Neural Information Processing, School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China

Abstract

In the present study, the correlated activities of adjacent ganglion cells of transient subtype in response to full-field white light stimulation were investigated in the chicken retina. Pharmacological studies and cross-correlation analysis demonstrated that application of the GABAA receptor antagonist bicuculline (BIC) significantly down-regulated the correlation strength while increasing the firing activities. Meanwhile, application of the GABAA receptor agonist muscimol (MUS) potentiated the correlated activities while decreasing the firing rates. However, application of the GABAC receptor antagonist (1,2,5,6-Tetrahydropyridin-4-yl)methylphosphinic acid (TPMPA) did not have a consistent influence on either the firing rates or the correlation strength. These results suggest that in the chicken retina, correlated activities among neighborhood transient ganglion cells can be increased while firing activities are reduced with the activation of GABAA receptors. The GABAA-receptor-mediated inhibitory pathway may be critical for improving the efficiency of visual information transmission.

Key words: vision; inhibition; GABAA receptor; correlation study

收稿日期：2008-12-09　　录用日期：2009-01-05

通讯作者：梁培基　　E-mail: pjliang@sjtu.edu.cn

引用本文：

刘雪, 张莹莹, 龚海庆, 梁培基. GABAA 受体抑制性通路增强视网膜神经节细胞活动的相关性[J]. 生理学报 2009; 61 (2): 99-107.

LIU Xue, ZHANG Ying-Ying, GONG Hai-Qing, LIANG Pei-Ji. The GABAA receptor mediated inhibitory pathway increases the correlated activities in retinal ganglion cells. Acta Physiol Sin 2009; 61 (2): 99-107 (in Chinese with English abstract).