Mouse photoreceptors are electrically coupled via gap junctions, but the relative importance of rod/rod, cone/cone, or rod/cone coupling is unknown. Furthermore, while connexin36 (Cx36) is expressed by cones, the identity of the rod connexin has been controversial. We report that FACS-sorted rods and cones both express Cx36 but no other connexins. We created rod- and cone-specific Cx36 knockout mice to dissect the photoreceptor network. In the wild type, Cx36 plaques at rod/cone contacts accounted for more than 95% of photoreceptor labeling and paired recordings showed the transjunctional conductance between rods and cones was ~300 pS. When Cx36 was eliminated on one side of the gap junction, in either conditional knockout, Cx36 labeling and rod/cone coupling were almost abolished. We could not detect direct rod/rod coupling, and cone/cone coupling was minor. Rod/cone coupling is so prevalent that indirect rod/cone/rod coupling via the network may account for previous reports of rod coupling.

小鼠感光器通过间隙连接进行电耦合，但杆/杆、锥/锥或杆/锥耦合的相对重要性尚不清楚。此外，虽然 connexin36 (Cx36) 由视锥细胞表达，但杆状连接蛋白的身份一直存在争议。我们报告 FACS 分类的视杆细胞和视锥细胞均表达Cx36，但不表达其他连接蛋白。我们创建了视杆细胞和视锥细胞特异性的Cx36敲除小鼠来剖析光感受器网络。在野生型中，视杆细胞/视锥细胞接触处的 Cx36 斑块占光感受器标记的 95% 以上，并且配对记录显示视杆细胞和视锥细胞之间的跨接点电导约为 300 pS。当Cx36在间隙连接的一侧被消除时，在任一条件敲除中，Cx36 标记和杆/锥体偶联几乎被废除。我们无法检测到直接的杆/杆耦合，并且锥体/锥体耦合很小。杆/锥耦合如此普遍，以至于通过网络的间接杆/锥/杆耦合可能解释了之前关于杆耦合的报道。