ELECTROPHYSIOLOGICAL EVIDENCE FOR A MECHANISM 

 OF COLOR VISION IN THE GOLDFISHES 



E. F. MacNichol, Jr. 



M. L. WOLBARSHT 



H. G. Wagner 



Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, 



Maryland, and Physiology Division, Naval Medical Research Institute, National 



Naval Medical Center, Bethesda, Maryland 



Introduction 



The act of vision in the vertebrates encompasses not only the ab- 

 sorption of visible racHation by a photopigment and its transduction 

 into some sort of electrochemical energy by a mosaic of photoreceptors, 

 but also the encoding of the messages from these elements for trans- 

 mission to the brain by a relatively small number of optic nerve 

 fibers. In the brain the visual message is presumably processed further 

 and compared with previous information stored in the memory. Sig- 

 nals are derived and transmitted to the various effector organs which 

 change the organism's relationship to its environment. The objective 

 of visual research is to understand the whole system in terms of the 

 detailed operation of the individual functional units of which it is 

 composed. 



Certainly the logical and systematic way to begin such an investi- 

 gation is at the beginning, with the light-sensitive cells of the retina. 

 Wald (34) has given an excellent summary of what is known of the 

 photopigments contained in some of the receptor cells and has pointed 

 out that the pigments in other receptors have not been separated and 

 purified successfully because of their chemical similarity and very 

 small concentration in the retinal extracts. 



These are just the pigments we need to know about if we are to 

 understand color vision. Fortunately, Rushton (22) and his co- 



' The opinions or assertions contained herein are the private ones of the authors 

 and are not to be construed as official or reflecting the views of the Navy Depart- 

 ment or the naval service at large. 



= This research was supported in part by National Science Foundation Grant 

 G-7086. 



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