神经节细胞群体同步放电模式编码的感受野特性  

Characteristics of Receptive Field Encoded by Synchronized Firing Pattern of Ganglion Cell Group

作　　者：李瑶[1] 李浩[1] 龚海庆[1] 梁培基[1] 张溥明[1] 

机构地区：[1]上海交通大学生物医学工程系,上海200240

出　　处：《生物物理学报》2011年第3期211-221,共11页Acta Biophysica Sinica

基　　金：国家自然科学基金项目(60775034)

摘　　要：应用多电极同步记录技术,对牛蛙视网膜神经节细胞在伪随机棋盘格刺激下的放电活动进行胞外记录。依据记录到的神经节细胞放电情况,利用一种数据压缩算法,通过最大化压缩放电序列的信息熵,对多个神经节细胞进行群体划分,得到同步放电神经节细胞群体。利用基于动作电位的刺激平均法(spike triggered average,STA),分别计算出每个同步放电神经节细胞群体内单个神经节细胞放电活动所编码的感受野(单细胞感受野),以及群体内所有神经节细胞同步放电活动所编码的感受野(群体感受野)。计算结果显示,对于所有神经节细胞群体,约80%神经节细胞群体的群体感受野面积小于群体内所有单细胞感受野面积的平均值,约60%神经节细胞群体的群体感受野面积小于群体内任意单细胞感受野面积。在棋盘格刺激下,神经节细胞放电活动会发生对比度适应。进一步以群体感受野面积小于群体内任意单细胞感受野面积的神经节细胞群体为研究对象,考察群体感受野在对比度适应过程中的动态变化,结果显示,85%神经节细胞群体的群体感受野面积在适应后期变小。The firing activities of the bullfrog retinal ganglion cells（GC） under the pseu-random checker board stimulus were recorded in vitro by the multi-electrode recording technology.Based on the firing activities of the GCs recorded,the synchronous GC groups were identified by a data compression algorithm,which compresses the entropy of the spike trains in the maximal extent.For every synchronous GC group,the receptive field（RF） encoded by each single GC＇s firing activity（Single-cell-RF） and the RF encoded by the synchronized firing activity of all the GCs in the group（group-RF） were calculated by using the spike triggered average（STA） method.The results revealed that for all the GC groups,about 80% of group-RF sizes of the GC groups were smaller than the mean size of single-cell-RFs in the same groups and about 60% of group-RF sizes of the GC groups were smaller than any single-cell-RF size in the same groups.The firing activities of GCs had the property of contrast adaptation under the checkerboard stimulus.We chose the GC groups with group-RF size smaller than any single-cell-RF size to investigate the dynamics of group-RF during the early and late period of contrast adaptation.The results illustrated that 85% of group-RF sizes of the GC groups were reduced during the late period of adaptation.

关 键 词：视网膜神经节细胞 同步放电 感受野 对比度适应 

分 类 号：Q424[生物学—神经生物学]