Gap junction-mediated electrical coupling between retinal photoreceptors is an important determinant of photoreceptor function. Yet, quantitative measurements of the junctional conductance between coupled photoreceptors are required to fully assess the effects of coupling on visual performance. Such measurements have been obtained in salamander and other lower vertebrate retinas but are difficult to acquire in mammalian retinas, in part because of the much smaller size of photoreceptors in mammals. Here, we describe in detail a dual whole-cell patch-clamp technique we recently developed to measure the junctional conductance between photoreceptor pairs in the mouse retina. With this method, electrical coupling strength between mouse photoreceptors can be estimated with high accuracy and its impact on retinal processing of visual information further evaluated.
Keywords: Cx36; Dual patch clamp; Electrical coupling; Gap junction; Mouse; Photoreceptor.