Chatterjee Susmita, Merwine David K, Amthor Franklin R, Grzywacz Norberto M
Department of Biomedical Engineering, University of Southern California, Los Angeles, California 90089-1111, USA.
Vis Neurosci. 2007 Nov-Dec;24(6):827-43. doi: 10.1017/S0952523807070757.
Neighboring retinal ganglion cells often spike synchronously, but the possible function and mechanism of this synchrony is unclear. Recently, the strength of the fast correlation between ON-OFF directionally selective cells of the rabbit retina was shown to be stimulus dependent. Here, we extend that study, investigating stimulus-dependent correlation among multiple ganglion-cell classes, using multi-electrode recordings. Our results generalized those for directionally selective cells. All cell pairs exhibiting significant spike synchrony did it for an extended edge but rarely for full-field stimuli. The strength of this synchrony did not depend on the amplitude of the response and correlations could be present even when the cells' receptive fields did not overlap. In addition, correlations tended to be orientation selective in a manner predictable by the relative positions of the receptive fields. Finally, extended edges and full-field stimuli produced significantly greater and smaller correlations than predicted by chance respectively. We propose an amacrine-network model for the enhancement and depression of correlation. Such an apparently purposeful control of correlation adds evidence for retinal synchrony playing a functional role in vision.
相邻的视网膜神经节细胞常常同步放电，但这种同步性的可能功能和机制尚不清楚。最近，研究表明兔视网膜上的开-关方向选择性细胞之间快速相关性的强度依赖于刺激。在此，我们拓展了该项研究，采用多电极记录技术，研究多个神经节细胞类型之间的刺激依赖性相关性。我们的结果推广了方向选择性细胞的相关研究。所有表现出显著放电同步性的细胞对，都是对延伸边缘产生同步放电，而对全场刺激则很少产生同步放电。这种同步性的强度并不取决于反应的幅度，即使细胞的感受野不重叠，相关性也可能存在。此外，相关性倾向于以一种可由感受野的相对位置预测的方式具有方向选择性。最后，延伸边缘和全场刺激分别产生了比随机预测显著更大和更小的相关性。我们提出了一种无长突细胞网络模型来解释相关性的增强和抑制。这种对相关性的明显的有目的控制，为视网膜同步性在视觉中发挥功能作用增添了证据。
