Letter | Published:

A comparison of inhibition in orientation and spatial frequency selectivity of cat visual cortex

Nature volume 321, pages 237239 (15 May 1986) | Download Citation

Subjects

Abstract

Neurones in the visual cortex are highly selective for orientation1 and spatial frequency2,3 of visual stimuli. There is strong neurophy-siological evidence that orientation selectivity is enhanced by inhibitory interconnections between columns in the cortex which have different orientation sensitivities4–6, an idea which is supported by experiments using neuropharmacological manipulation7,8 or complex visual stimuli6. It has also been proposed that selectivity for spatial frequency is mediated in part by a similar mechanism to that for orientation, although evidence for this is based on special use of visual stimuli, which hampers interpretation of the findings9,10. We have therefore examined selectivity for both orientation and spatial frequency using a technique which allows direct inferences about inhibitory processes. Our method uses microiontophoresis of an excitatory amino acid to elevate maintained discharge of single neurones in the visual cortex. We then present visual stimuli both within and outside the range of orientations and spatial frequencies which cause a cell to respond with increased discharge. Our results show that orientations presented on either side of the responsive range usually produce clear suppression of maintained discharge. In marked contrast, spatial frequencies shown to either side of the responsive range have little or no effect on maintained activity. We conclude that there is an intracortical organization of inhibitory connections between cells tuned to different orientations but not different spatial frequencies.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & J. Physiol., Land. 160, 106–154 (1962).

  2. 2.

    , & J. Physiol., Lond. 203, 223–235 (1969).

  3. 3.

    & Vision Res. 16, 1255–1267 (1973).

  4. 4.

    , & Nature new Biol. 238, 124–126 (1972).

  5. 5.

    , & Expl Brain Res. 21, 251–274 (1974).

  6. 6.

    , & Proc. R. Soc. B216, 335–354 (1982).

  7. 7.

    J. Physiol., Lond. 250, 305–329 (1975); 289, 33–53 (1979).

  8. 8.

    , , & Brain Res. 194, 517–520 (1980).

  9. 9.

    & J. Physiol., Lond. 336, 359–376 (1983).

  10. 10.

    Invest. Ophthal. vis. Sci. 24, 229 (1983).

  11. 11.

    , & J. Neurophysiol. 54, 61–72 (1985).

  12. 12.

    & J. Neurophysiol. 28, 229–289 (1965).

  13. 13.

    J. Physiol., Lond. 268, 391–421 (1977).

  14. 14.

    , & Expl Brain Res. 6, 373–390 (1968).

Download references

Author information

Author notes

    • A. S. Ramoa

    Permanent address: Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude, Dept. de Farmacologia, Bloco J, Ilha Universitaria, 21941, Rio de Janeiro, Brazil.

Affiliations

  1. Group in Neurobiology, School of Optometry, University of California, Berkeley, California 94720, USA

    • A. S. Ramoa
    • , M. Shadlen
    • , B. C. Skottun
    •  & R. D. Freeman

Authors

  1. Search for A. S. Ramoa in:

  2. Search for M. Shadlen in:

  3. Search for B. C. Skottun in:

  4. Search for R. D. Freeman in:

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/321237a0

Further reading Further reading

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.