Figure 2.

The mammalian retina uses electrical synapses in the vertical pathway from rod photoreceptors to ON-ganglion cells. In scotopic view, rod bipolar cells send signals to rod bipolar cells to excite AII amacrine cells through conventional synapses (green arrows). The AII cell forms electrical synapses (blue jagged line) with ON-cone bipolar cells, thus parasitizing the cone pathway. This pathway is lost in Cx36 knockout animals. Red arrows denote chemical inhibitory synapses. The diagram is modified from Strettoi, Dacheux and Raviola (J Comp Neurol 1994, 347:139-149).