Horizontal cells in turtle retinae are electrically coupled via gap junctions, and the input
resistances of the cells are too low to be measured. However, intracellular injection of
arachidonic acid into horizontal cells caused great increases in the input resistances of the
cells, and the cells could be easily polarized by intracellular current injection. The injection
of arachidonic acid also caused decrease in light responses of horizontal cells to surround
illumination, and blocked dye-couplings with Lucifer Yellow CH. On the other hand, injection …