SOME MECHANISMS OF COLOR RECEPTION FOUND BY ANALYZING THE ELECTRORETINOGRAM OF FROG

PART 1. COLOR CHARACTERISTICS OF THE MULTIPLE OFF-RESPONSE AND NUMBER OF RETINAL ELEMENTS

Abstract

The character of each wavelet in the multiple off-response was investigated in ERG of isolated frog's eyes at a definite low temperature, by using color illuminations of physically equal energy and of equal bleaching efficiency on visual purple. The results obtained were as follows.
A series of multiple off-wavelets due to white-light was found to contain patterns of specific response to colors-red, blue, green and blue in time order-of which the last blue rise was due to the activity of rods and all other earlier rises to the cone system.
Similar results were obtained in experiments on selective adaptation to definite colors so that a particular rise in the multiple off-response was inhibited by adaptation to a definite color and the inhibited peak contrarily, appeared markedly enhanced after removal of the adapted light.
Each main rise for any of the three original colors in the multiple off-response occasionally appeared as a group of smaller peaks. Thus the total number of multiple off-wavelets inherent in ERG may be at least six or more, suggesting the presence of so many kinds of retinal elements in the frog's eye.
The nature and origin of multiple ERG were discussed in reference to several authoritative works on the subject.