Observations on rod coupling in the isolated retina of Bufo marinus

Rod coupling was studied in the superfused isolated retina of Bufo marinus. Pairs of interacting rods were simultaneously impaled; current injected into one rod caused a current-induced potential in the second rod. Current-induced potentials and input resistance were monitored while changing the superfusate. Interactions were not reduced by removing extracellular Na+ or Cl-, indicating that these conductances do not mediate coupling. Interactions were not eliminated by altering extracellular Ca2+ or decreasing intracellular pH; the interactions are thus resistant to treatments that uncouple cels in other systems.