Blue cone input to the photopic electroretinogram of the turtle Pseudemys

Abstract

Chromatic adaptation and response averaging were used to determine if blue cone input could be identified in the photopic ERG of the turtle, Pseudemys scripta elegans. In addition to the long wavelength peak near 630 nm typically seen in Pseudemys action spectra, a short-wavelength peak near 460 nm was also found when 666 or 566 nm adapting fields were used. It is concluded that blue cones contribute to the photopic Pseudemys ERG and that the blue cone system interacts with the red and green cone systems in this species.