DENDRITES OF ROD DOMINANT ON-BIPOLAR CELLS ARE COUPLED BY GAP-JUNCTIONS IN CARP RETINA

Gap junctions are supposed to be the anatomical substrate for electrical coupling between neurons. In fish retina, bipolar cells are electrically coupled and their receptive field diameters are always larger than dendritic field size, however, gap junctions have not been described between dendrites of bipolar cells. In this paper, using immunostaining for protein kinase C, we show that every rod dominant ON-bipolar cell is connected with its neighboring dendrites by gap junctions forming a plexus in the outer plexiform layer. These dendritic processes provide the site of electrical coupling. We suggest that dendrites of bipolar cells could be involved in lateral pathways in retina.