Horizontal cell connections with short wavelength‐sensitive cones in the retina: A comparison between New World and Old World primates

Abstract

Recent studies in the Old World macaque monkey have shown that the two horizontal cell types H1 and H2 differ with respect to their connections to short wavelength-sensitive (SWS) cones. We wanted to establish whether this pattern of connectivity is common to all primates. The connections of horizontal cells with SWS cones were studied in the retinas of two species of New World (marmoset and tamarin) and two species of Old World (orangutan and chimpanzee) primates by using a double-labelling technique. Horizontal cells were labelled with DiI and then photoconverted; SWS cones were labelled immunocytochemically. The marmoset shows a sex-linked polymorphism of colour vision: All males are dichromats, whereas most females are trichromats. In contrast, Old World primates are usually trichromats. Our results show that the horizontal cells of both New World and Old World primates have a comparable pattern of connectivity with SWS cones and thus indicate that the wiring of horizontal cells with SWS cones does not differ between dichromats and trichromats and is common to all primates. The H1 cells make no or only sparse contact with SWS cones. In marmoset, H1 cells have on average 0.8% of their dendritic terminals at SWS cones. The H2 cells contact all SWS cones in their dendritic field. In marmoset, H2 cells have on average 11.8% of their dendritic terminals at SWS cones. The axon of H2 cells contacts SWS cones but presumably also contacts other cones.

Irregular S-cone mosaics in felid retinas Spatial interaction with axonless horizontal cells, revealed by cross correlation

“…19,20 The specific role of these cell types' dendritic trees, both connecting to cones, 21,22 has remained an enigma. For primate HC's, it has been shown [23][24][25][26] that a weighting of connectivity exists with respect to the two major classes of cones. H2-HC's (possibly a modified axonless type 20 ) have elevated connection densities to S cones within their dendritic field but also connect to long-wavelengthsensitive (L) and middle-wavelength-sensitive (M) cones.…”

Limits of Spatial Vision in Sumatran Orangutans (Pongo abelii)

“…Montiani-Ferreira et al (2010) noted that, while current knowledge about orangutan ocular anatomy and physiology is limited, orangutan eye physiology is similar enough to human eye physiology that human doctors were able to perform successful cataract surgery on a captive Bornean orangutan. Post mortem anatomical examination of the connections of short wavelength-sensitive (SWS) cones and horizontal cells in the retinas of a Bornean orangutan and a chimpanzee revealed similarity to humans in terms of the pattern of H1 versus H2 connections (Chan & Grünert, 1998). However, no other information about orangutan retinal organization is available.…”

“…For example, there are differences in color vision and visual acuity across nocturnal, diurnal, and cathemeral primates (Jacobs, 1977(Jacobs, , 1996Kirk, 2004;Matsui, Go, & Niimura, 2010;Ordy & Samorajski, 1968;Veilleux & Kirk, 2014). Eye morphology and visual system anatomy and physiology are similar within Old World monkeys and apes, but differences exist between these species and New World primates (Chan & Grünert, 1998;Waitt & Buchanan-Smith, 2006), and between haplorhine and strepsirrhine suborders of primates (Kirk, 2004;Veilleux & Kirk, 2009). Our closest relatives are the other great apes, yet there is limited information about either behavioral or physiological aspects of vision in these species.…”

V-Proportion: A method based on the Voronoi diagram to study spatial relations in neuronal mosaics of the retina

“…A positive spatial dependency between two different populations of neurons may be an indicator of some connection patterns between them [11,12,13,14]. The spatial information is moreover helpful to study dependencies during development [15].…”