Effects of local cobalt chloride injection on lateral spread of signals in fish (roach) retina.

There is extensive spatial summation in electrical responses of both horizontal and amacrine cells of the fish retina. The effect of locally perfused cobalt chloride on the lateral spread of signals along the layers of these interneurones has been studied in the roach (Rutilus rutilis) retina. It is shown that lateral transmission is blocked in amacrine but not in horizontal cells and this result is examined in relation to the synaptic coupling of the interneurones.