Density of cones and ganglion cells was studied in horizontal sections of retina in the rhesus monkey (Macaca, mulatta) and the squirrel monkey (Saimiri sciureus). The lower angular density of cones in the fovea of Saimiri correlates with its visual acuity, which is poorer than that of Macaca (0.74 and 0.65 min of arc respectively). Cone density falls more steeply with angular eccentricity from the fovea in Saimiri, in accordance with its relatively poorer peripheral acuity. Comparable results were obtained with retinal ganglion cells, but the comparisons at the fovea itself are more difficult because of the lateral displacement of these elements in the foveal region.
The cortical magnification of the visual field (that is, the number of mm of cortex per degree of visual field) is lower for both the foveal and parafoveal representations at the striate cortex in Saimiri. This was correlated with its poorer foveal and parafoveal acuity. It was shown that with increasing eccentricity from the fovea, the fall in the magnification of the visual field at the striate cortex is approximately proportional to the decrease in ganglion cell density at the retina. The results of this study, in which acuity and topography of the visual system are compared in two species of monkey, are consistent with the view that both retinal topography, and the cortical magnification of the visual field, are closely related to visual acuity.
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Abercrombie, M.: Estimation of nuclear population from microtome sections. Anat. Rec. 94, 239–247 (1946).
Cowey, A.: Projection of the retina onto striate and prestriate cortex in the squirrel monkey, Saimiri sciureus. J. Neurophysiol. 27, 366–393 (1964).
—: Perimetric study of field defects in monkeys after retinal and cortical ablations. Quart. J. exp. Psychol. 19, 232–245 (1967).
—, Ellis, C.M.: Visual acuity of rhesus and squirrel monkeys. J. comp. physiol. Psychol. 64, 80–84 (1967).
—: The cortical representation of the retina in squirrel and rhesus monkeys and its relation to visual acuity. J. exp. Neurol. 24, 374–385 (1963).
Daniel, P.M., Whitteridge, D.: The representation of the visual field on the cerebral cortex in monkeys. J. Physiol. (Lond.) 159, 203–221 (1961).
Duke-Elder, W.S.: Text-book of Ophthalmology, Vol. I. London: Henry Kimpton 1932.
Østerberg, G.: Topography of the layer of rods and cones in the human retina. Acta ophthal. (Kbh.) 65, Suppl., 1–102 (1935).
Polyak, S.: The main afferent fiber systems of the cerebral cortex in primates. University of California Publication in Anatomy, 2. Berkeley: University of California Press 1932.
—: The vertebrate visual system. Ed. by H. Klüver, Chicago/Ill.: University of Chicago Press 1957.
Stone, J.: A quantitative analysis of the distribution of ganglion cells in the cat's retina. J. comp. Neurol. 124, 337–352 (1965).
Van Buren, K.M.: The retinal ganglion cell layer. Springfield/Ill.: Charles Thomas 1963.
Weiskrantz, L., Cowey, A.: Comparison of the effects of striate cortex and retinal lesions on visual acuity in monkeys. Science 155, 104–106 (1967).
Weymouth, F.W.: Visual sensory units and the minimal angle of resolution. Amer. J. Ophthal. 46, 102–114 (1958).
Whitteridge, D.: Geometrical relations between the retina and the visual cortex. In: Mathematics and computer science in biology and medicine. London: Medical Research Council 1965.
This work was supported by Medical Research Council Grant G.967/2/B. We wish to thank Mrs L. Bowman and Mr D. Canwell for their help in preparing histological material.
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Rolls, E.T., Cowey, A. Topography of the retina and striate cortex and its relationship to visual acuity in rhesus monkeys and squirrel monkeys. Exp Brain Res 10, 298–310 (1970). https://doi.org/10.1007/BF00235053
- Visual acuity
- Ganglion cells
- Striate cortex