Functional consequences of heterotypic retinal ganglion cell coupling

神经元通过传统突触的化学传递和电传递进行交流 通过缝隙连接。电传递在哺乳动物的视网膜中得到了很好的研究，在那里缝隙连接 存在于所有五大类神经元之间。视网膜神经节细胞(RGC)，视网膜的输出细胞， 包括哺乳动物中的约40种功能类型。RGC之间的缝隙连接耦合一直被描述 “同型”，即在相同类型的RGC之间。我们第一次发现了异型 小鼠视网膜中两个不同类型的RGC之间的电耦合，称为F-minion和F-mini OFF RGC。 异型RGC偶联的存在打破了RGC通道功能平行的规律 这就需要对耦合在视网膜计算中的作用有新的看法。该项目旨在探索 异型RGC偶联通过两个特定目的在F-mini网络中的功能作用。在目标1中，我们将 确定F-minion和F-mini OFF RGC之间的偶联是否创建了一条新的混合和 关闭视网膜内部的信号。在目标2中，我们将确定运动刺激的哪些特征由 F-minion和F-mini OFF RGC之间的同步尖峰。 拟议的研究将促进我们对化学和电突触输入如何相互作用的理解 进行神经计算，以及并行通路之间的信号共享如何有助于感觉 编码。

Neurons communicate using both chemical transmission at traditional synapses and electrical transmission through gap junctions. Electrical transmission is well studied in the mammalian retina, where gap junctions exist between all five major classes of neurons. Retinal ganglion cells (RGCs), the output cells of the retina, comprise ~40 functional types in mammals. Gap junctional coupling among RGCs has always been described as “homotypic,” that is, between RGCs of the same type. We have discovered, for the first time, heterotypic electrical coupling in the mouse retina, between two RGCs of different types, called F-miniON and F-miniOFF RGCs. The existence of heterotypic RGC coupling breaks the rule of functional parallelism between RGC channels and requires new ideas about the role of coupling in retinal computation. This project aims to explore the functional role of heterotypic RGC coupling in the F-mini network through two specific aims. In Aim 1 we will determine whether coupling between F-miniON and F-miniOFF RGCs creates a novel pathway for mixing ON and OFF signals in the inner retina. In Aim 2 we will determine which features of moving stimuli are encoded by synchronized spiking between F-miniON and F-miniOFF RGCs. The proposed studies will advance our understanding of how chemical and electrical synaptic inputs interact to perform neural computations and how sharing of signals between parallel pathways contributes to sensory encoding.