Organization of the human trichromatic cone mosaic. J Neurosci 2005 Oct 19;25(42):9669-79
Date
10/21/2005Pubmed ID
16237171Pubmed Central ID
PMC6725723DOI
10.1523/JNEUROSCI.2414-05.2005Scopus ID
2-s2.0-27144497539 (requires institutional sign-in at Scopus site) 320 CitationsAbstract
Using high-resolution adaptive-optics imaging combined with retinal densitometry, we characterized the arrangement of short- (S), middle- (M), and long- (L) wavelength-sensitive cones in eight human foveal mosaics. As suggested by previous studies, we found males with normal color vision that varied in the ratio of L to M cones (from 1.1:1 to 16.5:1). We also found a protan carrier with an even more extreme L:M ratio (0.37:1). All subjects had nearly identical S-cone densities, indicating independence of the developmental mechanism that governs the relative numerosity of L/M and S cones. L:M cone ratio estimates were correlated highly with those obtained in the same eyes using the flicker photometric electroretinogram (ERG), although the comparison indicates that the signal from each M cone makes a larger contribution to the ERG than each L cone. Although all subjects had highly disordered arrangements of L and M cones, three subjects showed evidence for departures from a strictly random rule for assigning the L and M cone photopigments. In two retinas, these departures corresponded to local clumping of cones of like type. In a third retina, the L:M cone ratio differed significantly at two retinal locations on opposite sides of the fovea. These results suggest that the assignment of L and M pigment, although highly irregular, is not a completely random process. Surprisingly, in the protan carrier, in which X-chromosome inactivation would favor L- or M-cone clumping, there was no evidence of clumping, perhaps as a result of cone migration during foveal development.
Author List
Hofer H, Carroll J, Neitz J, Neitz M, Williams DRAuthor
Joseph J. Carroll PhD Director, Professor in the Ophthalmology and Visual Sciences department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Color PerceptionColor Vision Defects
Electroretinography
Female
Humans
Male
Retinal Cone Photoreceptor Cells
