Preferential representation of the fovea in the primary visual cortex.

Azzopardi P., Cowey A.

The retinal fovea, which corresponds to the central degree or so of vision, is spatially over-represented in the visual cortex. It is about 0.01% of retina area, but at least 8% of the striate cortex. Does this simply reflect an equivalently uneven distribution of ganglion cells in the retina, or is the cortical representation of the fovea preferentially expanded? The answer hinges on the resolution of long-standing discrepancies between the retinal and cortical magnification factors. We approached the problem in a different way, using a retrograde transneuronal tracer from cortex to retina to relate directly the number of ganglion cells projecting to marked areas of striate cortex. We report here that ganglion cells near the fovea were allocated 3.3 to 5.9 times more cortical tissue than more peripheral ones, and conclude that the cortical representation of the most central retina is much greater than expected from the density of its ganglion cells.

DOI

10.1038/361719a0

Type

Journal article

Journal

Nature

Publication Date

25/02/1993

Volume

361

Pages

719 - 721

Keywords

Animals, Axonal Transport, Brain Mapping, Fovea Centralis, Horseradish Peroxidase, Macaca fascicularis, Macaca mulatta, Mathematics, Models, Neurological, Retinal Ganglion Cells, Vision, Ocular, Visual Cortex, Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate, Wheat Germ Agglutinins

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