Synaptic input to small bistratified (blue-ON) ganglion cells in the retina of a New World monkey, the marmosetCallithrix jacchus

AbstractWe studied the anatomical substrates of spatial vision in a New World monkey, the marmoset Callithrix jacchus. This species has good visual acuity and a foveal specialization which is qualitatively similar to that of humans and other Old World primates.We measured the spatial density of retinal ganglion cells and photoreceptors, and calculated the relative numbers of these cell populations. We find that ganglion cells outnumber photoreceptors by between 2.4:1 and 4.2:1 in the fovea. The peak sampling density of ganglion cells is close to 550,000 cells/mm2. This value falls by almost 1000-fold between the fovea and peripheral retina; a value which approaches recent estimates of the centroperipheral ganglion cell gradient for human and macaque monkey retina and primary visual cortex. The marmoset shows a sex-linked polymorphism of color vision: all male and some female marmosets are dichromats. Six of the retinas used in the present study came from animals whose chromatic phenotype was identified in electrophysiological experiments and confirmed by polymerase chain reaction (PCR) amplification of cone opsin encoding genes. One animal was a trichromat and the others were dichromats. Antibodies against short wavelength-sensitive (SWS) cones labeled close to 8% of all cones near the fovea of onedichromat animal, consistent with electrophysiological evidence that the SWS system is present inall marmosets. The topography and spatial density of cone photoreceptors and ganglion cells was similar to that reported for macaque retina, and we found no obvious difference between dichromatic and trichromatic marmoset retinas. These results reinforce the view that the main determinate of primate foveal topography is the requirement for maximal spatial resolution.

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Distribution of bipolar input to midget and parasol ganglion cells in marmoset retina

Visual Neuroscience ◽

10.1017/s0952523808080073 ◽

2008 ◽

Vol 25 (1) ◽

pp. 67-76 ◽

Cited By ~ 14

Author(s):

BAHAR ERIKÖZ ◽

PATRICIA R. JUSUF ◽

KUMIKO A. PERCIVAL ◽

ULRIKE GRÜNERT

Keyword(s):

Ampa Receptor ◽

Synaptic Input ◽

New World ◽

Ganglion Cells ◽

World Monkey ◽

Dendritic Tree ◽

Retinal Ganglion ◽

Response Characteristics ◽

Different Types ◽

Synaptic Markers

Different types of retinal ganglion cell show differences in their response properties. Here we investigated the question of whether these differences are related to the distribution of the synaptic input to the dendritic tree. We measured the distribution and density of synaptic input to the dendrites of midget and parasol ganglion cells in the retina of a New World monkey, the marmoset,Callithrix jacchus. Ganglion cells were retrogradely labeled by dye injection into parvocellular or magnocellular regions of the lateral geniculate nucleus and subsequently photo-filled. Presumed bipolar cell synapses were identified immunocytochemically using antibodies against the ribbon protein CtBP2 or the GluR4 subunit of the AMPA receptor. For all cells, colocalized immunoreactive puncta were distributed across the entire dendritic tree. The density of the presumed bipolar input to midget ganglion cells was comparable for both synaptic markers, suggesting that the AMPA receptor GluR4 subunit is expressed at all synapses between midget bipolar and midget ganglion cells. Midget ganglion cells had an average of nine colocalized immunoreactive puncta per 100 μm2dendritic surface, and parasol cells had an average of seven colocalized immunoreactive puncta per 100 μm2dendritic surface. The densities were comparable in different regions of the dendritic tree and were not influenced by the location of the cells with respect to the fovea. Our findings suggest that the differences in the response characteristics of midget and parasol cells are not due to differences in the density of synaptic input to their dendritic tree.

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Morphology of retinal ganglion cells in a New World monkey, the marmosetCallithrix jacchus

The Journal of Comparative Neurology ◽

10.1002/(sici)1096-9861(19960226)366:1<76::aid-cne6>3.0.co;2-h ◽

1996 ◽

Vol 366 (1) ◽

pp. 76-92 ◽

Cited By ~ 71

Author(s):

Krishna K. Ghosh ◽

Ann K. Goodchild ◽

Ann E. Sefton ◽

Paul R. Martin

Keyword(s):

Retinal Ganglion Cells ◽

New World ◽

Ganglion Cells ◽

World Monkey ◽

Retinal Ganglion ◽

New World Monkey

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Selective degeneration of the parvocellular-projecting retinal ganglion cells in a New World monkey, Saimiri sciureus

Brain Research ◽

10.1016/0006-8993(89)90781-6 ◽

1989 ◽

Vol 499 (2) ◽

pp. 325-332 ◽

Cited By ~ 8

Author(s):

James J. Lynch ◽

Thomas A. Eskin ◽

William H. Merigan

Keyword(s):

Retinal Ganglion Cells ◽

New World ◽

Ganglion Cells ◽

World Monkey ◽

Saimiri Sciureus ◽

Retinal Ganglion ◽

New World Monkey

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CENP-B box, a nucleotide motif involved in centromere formation, occurs in a New World monkey

Biology Letters ◽

10.1098/rsbl.2015.0817 ◽

2016 ◽

Vol 12 (3) ◽

pp. 20150817 ◽

Cited By ~ 9

Author(s):

Aorarat Suntronpong ◽

Kazuto Kugou ◽

Hiroshi Masumoto ◽

Kornsorn Srikulnath ◽

Kazuhiko Ohshima ◽

...

Keyword(s):

Repetitive Dna ◽

New World ◽

World Monkey ◽

Common Marmoset ◽

Alpha Satellite ◽

Satellite Repeat ◽

New World Monkey ◽

Alpha Satellite Dna ◽

Negative Results ◽

Contig Sequence

Centromere protein B (CENP-B) is one of the major proteins involved in centromere formation, binding to centromeric repetitive DNA by recognizing a 17 bp motif called the CENP-B box. Hominids (humans and great apes) carry large numbers of CENP-B boxes in alpha satellite DNA (AS, the major centromeric repetitive DNA of simian primates). Only negative results have been reported regarding the presence of the CENP-B box in other primate taxa. Consequently, it is widely believed that the CENP-B box is confined, within primates, to the hominids. We report here that the common marmoset, a New World monkey, contains an abundance of CENP-B boxes in its AS. First, in a long contig sequence we constructed and analysed, we identified the motif in 17 of the 38 alpha satellite repeat units. We then sequenced terminal regions of additional clones and found the motif in many of them. Immunostaining of marmoset cells demonstrated that CENP-B binds to DNA in the centromeric regions of chromosomes. Therefore, functional CENP-B boxes are not confined to hominids. Our results indicate that the efficiency of identification of the CENP-B box may depend largely on the sequencing methods used, and that the CENP-B box in centromeric repetitive DNA may be more common than researchers previously thought.

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