Department of Ophthalmology, New York University Langone Medical Center, New York, New York, United States of America.
PLoS One. 2013 Jul 23;8(7):e69426. doi: 10.1371/journal.pone.0069426. Print 2013.
Neurons throughout the brain show spike activity that is temporally correlated to that expressed by their neighbors, yet the generating mechanism(s) remains unclear. In the retina, ganglion cells (GCs) show robust, concerted spiking that shapes the information transmitted to central targets. Here we report the synaptic circuits responsible for generating the different types of concerted spiking of GC neighbors in the mouse retina. The most precise concerted spiking was generated by reciprocal electrical coupling of GC neighbors via gap junctions, whereas indirect electrical coupling to a common cohort of amacrine cells generated the correlated activity with medium precision. In contrast, the correlated spiking with the lowest temporal precision was produced by shared synaptic inputs carrying photoreceptor noise. Overall, our results demonstrate that different synaptic circuits generate the discrete types of GC correlated activity. Moreover, our findings expand our understanding of the roles of gap junctions in the retina, showing that they are essential for generating all forms of concerted GC activity transmitted to central brain targets.
大脑中的神经元表现出与邻近神经元在时间上相关的尖峰活动，但产生这种活动的机制尚不清楚。在视网膜中，神经节细胞（GCs）表现出强烈的、协调一致的尖峰活动，这种活动塑造了向中枢靶区传递的信息。在这里，我们报告了负责产生小鼠视网膜中 GC 邻近细胞不同类型协调尖峰活动的突触回路。最精确的协调尖峰活动是通过 GC 相邻细胞的缝隙连接进行的互惠电耦合产生的，而间接电耦合到一个共同的无长突细胞群则产生了具有中等精度的相关活动。相比之下，具有最低时间精度的相关尖峰活动是由携带光感受器噪声的共享突触输入产生的。总的来说，我们的结果表明，不同的突触回路产生了离散的 GC 相关活动类型。此外，我们的发现扩展了我们对视网膜中缝隙连接作用的理解，表明它们对于传递到中枢大脑靶区的所有形式的协调 GC 活动都是必不可少的。
