Abstract
IT has long been known that vertebrate photoreceptors can signal the absorption of single quanta of light1. The extraordinary sensitivity of the visual system is usually ascribed both to the sensitivity of the photoreceptors and to the integration of their signals by higher-order neurones. A more complete explanation of visual sensitivity could be given if it were possible to record the response of receptors at the visual threshold. Unfortunately, it has not been possible to do this at the absolute threshold, largely because of interactions between receptors2. Near the absolute threshold only a small proportion of the receptors absorb quanta, but the photocurrent from these cells spreads through electronic synapses3 to many other cells. Thus the voltage responses in the receptors are non-uniform, and it is not possible to tell which responses contribute to the threshold. Fortunately this difficulty does not arise at the increment threshold since in the presence of bright background light, the variation in response from one receptor to the next is minimal. The differences among the receptors in the number of quanta caught will be much less important than at absolute threshold, and the connections between the receptors will tend to equalise their voltages. In this report we compare receptor responses to behavioural responses in the light-adapted turtle and show that the receptor response at threshold is only a few microvolts in amplitude.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Hecht, S., Schlaer, S., and Pirenne, M. H., J. gen. Physiol., 25, 819–840 (1942).
Fain, G. L., Science 187, 838–841 (1975).
Fain, G. L., Gold, G. H., and Dowling, J. E., Cold Spring Harb. Symp. quant. Biol. 40, 547–561 (1976).
Baylor, D. A., and Hodgkin, A. L., J. Physiol., Lond., 242, 729–758 (1974).
Baylor, D. A., and Hodgkin, A. L., J. Physiol., Lond. 234, 163–198 (1973).
Fain, G. L., J. Physiol. 261, 71–101 (1976).
Muntz, W. R. A., and Sokol, S., Vision Res. 7, 729–741 (1967).
Muntz, W. R. A., and Northmore, D. P. M., Vision Res. 8, 787–800 (1968).
Granda, A. M., Maxwell, J. H., and Zwick, H., Vision Res. 12, 653–672 (1972).
Fuortes, M. G. F., and Simon, E. J., J. Physiol., Lond., 240, 177–198 (1974).
Baylor, D. A., Fuortes, M. G. F., and O'Bryan, P. M., J. Physiol., Lond., 214, 265–294 (1971).
Bennett, M. V. L., in Fish Physiology 5 (edit. by Hoar, W. S., and Randall, D. J.), 493–574 (Academic, New York, 1971).
Steinbach, A. B., in Synaptic Transmission and Neuronal Interaction (edit. by Bennett, M. V. L.), 105–140 (Raven, New York, 1974).
Gray, E. G., and Pease, H. L., Brain Res. 35, 1–15 (1971).
Raviola, E., and Gilula, N. B., J. Cell. Biol. 65, 192–222 (1975).
Author information
Authors and Affiliations
Additional information
The erratum article can be found online at https://doi.org/10.1038/270191a0
Rights and permissions
About this article
Cite this article
FAIN, G., GRANDA, A. & MAXWELL, J. Voltage signal of photoreceptors at visual threshold. Nature 265, 181–183 (1977). https://doi.org/10.1038/265181a0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/265181a0
This article is cited by
-
An evaluation of sensory noise in the human visual system
Biological Cybernetics (1991)
-
Voltage-dependence of cobalt-induced blockade of synaptic transmission between photoreceptors and horizontal retinal cells
Neurophysiology (1988)
-
Current noise generated by electrogenic ion pumps
European Biophysics Journal (1984)
-
Slow potentials in nonspiking optic nerve fibers in the peripheral visual system ofLimulus
Journal of Comparative Physiology ? A (1981)
-
Photoreceptor signals at visual threshold
Nature (1980)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.