 |
||||
|
||||
|
||||
|
||||
Previous Article | Next Article
The Journal of Neuroscience, May 1, 2003, 23(9):3771
A Precise Retinotopic Map of Primate Striate Cortex Generated from the Representation of Angioscotomas
Daniel L. Adams and Jonathan C. Horton Beckman Vision Center, University of California, San Francisco, San Francisco, California 94143-0730
Shadows cast by retinal blood vessels are represented in striate cortex of the squirrel monkey. Their pattern was exploited to generate a true retinotopic map of V1. For calibration, retinal landmarks were projected onto a tangent screen to measure their visual field location. Next, the retina was warped onto striate cortex, distorting it as necessary to match each retinal vessel to its cortical representation. Maps from four hemispheres of two normal adult squirrel monkeys were created and used to derive expressions for cortical magnification factor (M). A mean map was produced by averaging the individual maps. To address the controversial issue of whether the ratio of retinal ganglion cell (RGC) density to M is constant at all eccentricities, we stained a retinal whole mount from one of the two monkeys for Nissl substance. A ganglion cell density map was compiled by sampling the concentration of cells at 171 retinal points. Allowance was made for displaced amacrine cells and for the centripetal displacement of RGCs from central photoreceptors. After these corrections the V1 surface area and RGC density were compared at each eccentricity. The cortical representation of the macula was found to be amplified, even beyond the magnification expected from its high density of RGCs. For example, the central 4° of visual field were allotted 27% of the surface area of V1 but were supplied by only 12% of RGCs. We conclude that, in monkey striate cortex, more tissue is allocated per ganglion cell for the analysis of information emanating from the macula as compared with the peripheral retina.
Key words: blind spot; monocular crescent; retina; blood vessel; flat-mount; ocular dominance column; cytochrome oxidase; magnification factor; anisotropy; displaced amacrine cell; GABA; retinal ganglion cell; cone; macula; Henle fiber layer
Copyright © 2003 Society for Neuroscience 0270-6474/03/2393771-19$05.00/0
This article has been cited by other articles:
X. Huang and M. A. Paradiso
V1 Response Timing and Surface Filling-In
J Neurophysiol, July 1, 2008; 100(1): 539 - 547.
[Abstract] [Full Text] [PDF]
Z. Yang, D. J. Heeger, and E. Seidemann
Rapid and Precise Retinotopic Mapping of the Visual Cortex Obtained by Voltage-Sensitive Dye Imaging in the Behaving Monkey
J Neurophysiol, August 1, 2007; 98(2): 1002 - 1014.
[Abstract] [Full Text] [PDF]
M. M. Schira, A. R. Wade, and C. W. Tyler
Two-Dimensional Mapping of the Central and Parafoveal Visual Field to Human Visual Cortex
J Neurophysiol, June 1, 2007; 97(6): 4284 - 4295.
[Abstract] [Full Text] [PDF]
J. Larsson and D. J. Heeger
Two Retinotopic Visual Areas in Human Lateral Occipital Cortex
J. Neurosci., December 20, 2006; 26(51): 13128 - 13142.
[Abstract] [Full Text] [PDF]
D. L. Adams and J. C. Horton
The Representation of Retinal Blood Vessels in Primate Striate Cortex
J. Neurosci., July 9, 2003; 23(14): 5984 - 5997.
[Abstract] [Full Text] [PDF]
|
|
|
|
 |
|