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Photoreceptor topography and cone-specific electroretinograms

Published online by Cambridge University Press:  05 April 2005

I.J. MURRAY
Affiliation:
Visual Sciences Laboratory, Department of Optometry and Neuroscience, University of Manchester Institute of Science and Technology, Manchester, UK
N.R.A. PARRY
Affiliation:
Visual Sciences Centre, Manchester Royal Eye Hospital, Oxford Rd, Manchester, UK
J. KREMERS
Affiliation:
Department of Visual Pathophysiology, University of Tubingen, Tubingen, Germany
M. STEPIEN
Affiliation:
Department of Visual Pathophysiology, University of Tubingen, Tubingen, Germany
A. SCHILD
Affiliation:
Department of Visual Pathophysiology, University of Tubingen, Tubingen, Germany

Abstract

It is implicit in many cone-specific ERG studies that the amplitude is proportional to the numbers of cones stimulated. The objective of these experiments was to test this idea by comparing ERGs obtained from different areas of the retina with histological data on cone-density distributions. The histology (Curcio et al., 1990) shows that the cumulative number of cones in the human retina increases exponentially with stimulus diameter between 0- and 40-deg eccentricity. L-, M-, and (L+M) cone-driven 30-Hz ERGs were obtained from a series of stimuli with one of the following configurations: (1) Circular stimuli of different angular subtense up to 70-deg diameter. (2) Annuli with 70-deg outer diameter but variable inner diameter. (3) Annuli of constant area but increasing eccentricity. Cone contrasts were equalized for each stimulus condition. The modulated and nonmodulated regions of the screen had the same mean hue and luminance. The data suggest that the L+M cone ERG amplitude increases with stimulus diameter in direct proportion to the estimated number of cones stimulated. Furthermore, the total L+M responses appear to be predicted from individual L and M responses by simple linear summation for both the disc and annular stimuli.

Type
Research Article
Copyright
© 2004 Cambridge University Press

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References

REFERENCES

Brainard, D.H., Calderone, J.B., Nugent, A.N., & Jacobs, G.H. (1999). Flicker ERG responses to stimuli parametrically modulated in color space. Investigative Ophthalmology and Visual Science 40(12), 28402847.Google Scholar
Bush, R.A. & Sieving, P.A. (1996). Inner retinal contributions to the primate photopic fast flicker electroretinogram. Journal of the Optical Society of America A 13, 557565.CrossRefGoogle Scholar
Curcio, C., Sloan, K., Kalina, R., & Hendrickson, A. (1990). Human photoreceptor topography. Journal of Comparative Neurology 292, 497523.CrossRefGoogle Scholar
Kremers, J. & Meierkord, S. (1999). Rod–cone interactions in deuteranopic observers: Models and dynamics. Vision Research 39, 33723385.CrossRefGoogle Scholar
Kremers, J., Usui, T., Scholl, H., & Sharpe, L. (1999). Cone signal contributions to electroretinograms in dichromats and trichromats. Investigative Ophthalmology and Visual Science 40(5), 920930.Google Scholar
Kondo, M. & Sieving, P.A. (2002). Post-photoreceptoral activity dominates primate photic 32 Hz ERG for sine, square, and pulsed stimuli. Investigative Opthalmology 43(7), 25002507.Google Scholar
Miyahara, E., Pokorny, J., Smith, V.C., & Baron, R. (1998). Color vision in two observers with highly biased LWS/MWS cone ratios. Vision Research 38, 601612.CrossRefGoogle Scholar
Mullen, K.T. & Kingdom, F.A.A. (2002). Differential distributions of red–green and blue–yellow cone opponency across the visual field. Visual Nueroscience 19, 109118.Google Scholar
Osterberg, G.A. (1935). Topography of the layer of rods and cones in the human retina. Acta Ophthalmologica 13 (Suppl. 6), 197.Google Scholar
Schnapf, J.L., Kraft, T.J., & Baylor, D.A. (1987). Spectral sensitivity of human cone photoreceptors. Nature 325, 439441.CrossRefGoogle Scholar
Scholl, H.P.N. & Kremers, J. (2000). Large phase differences between L-cone and M-cone driven electroretinograms in retinitis pigmentosa. Investigative Ophthalmology and Visual Science 41, 32253233.Google Scholar
Smith, V.C. & Pokorny, J. (1975). Spectral sensitivity of the foveal cone photopigments between 400 nm and 500 nm. Vision Research 15, 161171.CrossRefGoogle Scholar
Usui, T., Kremers, J., Sharpe, L.T., & Zrenner, E. (1998). Flicker cone electroretinogram in dichromats and trichromats. Vision Research 8, 32473251.Google Scholar
Wyszecki, G. & Stiles, W.S. (1982). Color science: Concepts and methods, quantitatitve data and formulae. 2nd ed. New York, NY: John Wiley & Sons.