Electrophysiological and spectral properties of second-order retinal neurons in the eel

Abstract

Several classes of second-order neurons have been electrophysiologically explored in immature European eels (Anguilla anguilla) from two distant and ecologically different localities tin Russia and Yugoslavia). The majority of L-horizontal cells (58 explored) had both rod and cone inputs, an uncommon phenomenon among teleosts. Spectral sensitivity characteristics of a number of horizontal and bipolar cells indicated that yellow-sensitive and green-sensitive cones coexist in the retina of the European eel, and that rods and green-sensitive cones contain similar visual pigments. Pronounced color-opponent properties, often taken as the capacity of color vision, were identified in one amacrine cell, apparently of the B/Y (or B/G) type. Differences in retinal structure and responsiveness between eels from the two localities, presumably due to differences in local conditions for growth, were less important than between eels of the yellow and silver stage.