Contribution of parasol-magnocellular pathway ganglion cells to foveal retina in macaque monkey

Ivan C K Ma; Subha Nasir-Ahmad; Sammy C S Lee; Ulrike Grünert; Paul R Martin

doi:10.1016/j.visres.2022.108154

Contribution of parasol-magnocellular pathway ganglion cells to foveal retina in macaque monkey

Vision Res. 2023 Jan:202:108154. doi: 10.1016/j.visres.2022.108154. Epub 2022 Nov 24.

Authors

Ivan C K Ma¹, Subha Nasir-Ahmad², Sammy C S Lee², Ulrike Grünert², Paul R Martin³

Affiliations

¹ The University of Sydney, Faculty of Medicine and Health, Save Sight Institute and Discipline of Ophthalmology, Sydney, NSW 2000, Australia.
² The University of Sydney, Faculty of Medicine and Health, Save Sight Institute and Discipline of Ophthalmology, Sydney, NSW 2000, Australia; The University of Sydney, Australian Research Council Centre of Excellence for Integrative Brain Function, Sydney, NSW 2000, Australia.
³ The University of Sydney, Faculty of Medicine and Health, Save Sight Institute and Discipline of Ophthalmology, Sydney, NSW 2000, Australia; The University of Sydney, Australian Research Council Centre of Excellence for Integrative Brain Function, Sydney, NSW 2000, Australia. Electronic address: paul.martin@sydney.edu.au.

PMID: 36436365
DOI: 10.1016/j.visres.2022.108154

Abstract

Parasol-magnocellular pathway ganglion cells form an important output stream of the primate retina and make a major contribution to visual motion detection. They are known to comprise ON and OFF type response polarities but the relative numbers of ON and OFF parasol cells, and the overall contribution of parasol cells to high-acuity foveal vision are not well understood. Here we use antibodies against carbonic anhydrase 8 (CA8) and intracellular injections of the liphilic dye DiI to show that CA8 selectively labels OFF parasol cells in macaque retina. By combined labeling with CA8 antibodies and a previously-described marker for parasol cells (GABA_A receptor antibodies), we show that ON and OFF parasol cells each comprise ∼ 6% of all ganglion cells in central retina (each peak density ∼ 3000 cells/mm² at 5 deg.), and each population comprises ∼ 10% of all ganglion cells in peripheral temporal retina. Thus, the spatial density of parasol cells in central retina is greater than reported by previous anatomical studies, and the central-peripheral gradient in parasol cell density is shallower than previously reported. The data nevertheless predict decline in spatial acuity with visual field eccentricity for both midget-parvocellular pathway and parasol-magnocellular pathway mediated visual functions. The spatial resolving power of the OFF parasol array (peak ∼ 7 cpd) falls short of macaque behavioral grating acuity by at least a factor of three throughout the retina.

Keywords: Magnocellular; Parasol; Primate; Retina; Visual Pathways.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Haplorhini
Macaca*
Retina / physiology
Retinal Ganglion Cells* / physiology
Visual Fields