Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 18 August 1967:
Vol. 157. no. 3790, pp. 813 - 816
DOI: 10.1126/science.157.3790.813
Prev | Table of Contents | Next

Articles

Molecular and Thermal Origins of Fast Photoelectric Effects in the Squid Retina

W. A. Hagins 1 and R. E. McGaughy 1

1 National Institute of Arthritis and Metabolic Diseases, Bethesda, Maryland

When a short, intense flash of light is absorbed by the outer segments of squid photoreceptors fixed in glutaraldehyde, a voltage appears briefly across the retina. The waveform depends on the relative amounts of rhodopsin and its various stable photoproducts present at the beginning of the flash. Each light-absorbing species present contributes a characteristic voltage component which is summed in the gross waveform. The heating effect of the absorbed light produces a small, long-lasting thermoelectric voltage as well. When this thermal effect is corrected for, interconversion of equal numbers of rhodopsin and acid metarhodopsin molecules by a flash results in a fast voltage waveform whose time integral is zero. Thus the charge flowing in one direction in the retina when rhodopsin is converted to acid metarhodopsin by one photon is apparently exactly reversed when acid metarhodopsin is reconverted to rhodopsin by another.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Limulus Rhodopsin: Rapid Return of Transient Intermediates to the Thermally Stable State.
A. Fein and R. A. Cone (1973)
Science 182, 495-497
   Abstract »    PDF »
Physiological Chemistry of the Eye.
A. Spector (1970)
Arch Ophthalmol 83, 506-522
   PDF »
Molecular Basis of Visual Excitation.
G. Wald (1968)
Science 162, 230-239
   PDF »
Membrane Origin of the Fast Photovoltage of Squid Retina.
W. A. Hagins and R. E. McGaughy (1968)
Science 159, 213-215
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)