Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY 10036.
Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY 10036
Proc Natl Acad Sci U S A. 2017 Nov 28;114(48):E10484-E10493. doi: 10.1073/pnas.1708261114. Epub 2017 Nov 13.
Coherent spike activity occurs between widely separated retinal ganglion cells (RGCs) in response to a large, contiguous object, but not to disjointed objects. Since the large spatial separation between the RGCs precludes common excitatory inputs from bipolar cells, the mechanism underlying this long-range coherence remains unclear. Here, we show that electrical coupling between RGCs and polyaxonal amacrine cells in mouse retina forms the synaptic mechanism responsible for long-range coherent activity in the retina. Pharmacological blockade of gap junctions or genetic ablation of connexin 36 (Cx36) subunits eliminates the long-range correlated spiking between RGCs. Moreover, we find that blockade of gap junctions or ablation of Cx36 significantly reduces the ability of mice to discriminate large, global objects from small, disjointed stimuli. Our results indicate that synchronous activity of RGCs, derived from electrical coupling with amacrine cells, encodes information critical to global object perception.
相干尖峰活动发生在视网膜神经节细胞(RGC)之间,以响应大的、连续的物体,而不是不连续的物体。由于 RGC 之间的大空间分离排除了双极细胞的共同兴奋性输入,因此这种长程相干性的机制尚不清楚。在这里,我们表明,在小鼠视网膜中,RGC 和多轴突无长突细胞之间的电耦合形成了负责视网膜长程相干活动的突触机制。药理学阻断缝隙连接或遗传消融连接蛋白 36(Cx36)亚基消除了 RGC 之间的长程相关尖峰。此外,我们发现,阻断缝隙连接或消融 Cx36 显著降低了小鼠区分大的、全局物体与小的、不连续刺激的能力。我们的结果表明,源自与无长突细胞的电耦合的 RGC 同步活动,编码了对全局物体感知至关重要的信息。