TY - JOUR
T1 - Reduced density of geniculocortical terminals in foveal layer 4A in the macaque primary visual cortex
T2 - relationship to S-cone density
AU - Garcia-Marin, Virginia
AU - Sundiang, Marina
AU - Hawken, Michael J.
N1 - Funding Information:
This work was supported by NIH grants EY17945 and P30EY013079. V.G-M was supported by the Spanish Ministry of Education, Science and Innovation (National R&D&I Plan 2008–2011, National Human Resources Mobility Programme, Postdoctoral Mobility in Foreign Centers, grant EX2009-0636). We thank Jenna Kelly for helpful suggestions and Claudia Farb, Yasmeen Afzal, and Tunazzina Ahmed for their technical support.
Publisher Copyright:
© 2014, Springer-Verlag Berlin Heidelberg.
PY - 2015/9/28
Y1 - 2015/9/28
N2 - The S-cone system is closely linked to the perception of blue/yellow. The trichromatic system of Old-World monkeys and humans has relatively few S-cones in the fovea. In this study, we investigated the distribution of putative S-cone afferents in macaques primary visual cortex (V1) which form a characteristic honeycomb arrangement in layer 4A. It was hypothesized that if there were a low number of S-cone opponent projecting neurons in central vision then this would be seen as a reduction in afferents in foveal layer 4A. Recent studies have shown that the vesicular glutamate transporter 2 (VGlut2) is a marker for thalamic afferent terminals in cortex. The distribution of VGlut2-immunoreactive (-ir) terminals was studied in the foveal and perifoveal representation of V1. It was found that there was a substantial reduction in the terminal density in the foveal representation: the density was 5–6 times lower in the foveal V1 than in regions representing perifoveal eccentricities of 1°–2° and beyond. These findings may provide the cortical substrate of foveal tritanopia, the reduced blue perceptual ability for small fields in the center of gaze.
AB - The S-cone system is closely linked to the perception of blue/yellow. The trichromatic system of Old-World monkeys and humans has relatively few S-cones in the fovea. In this study, we investigated the distribution of putative S-cone afferents in macaques primary visual cortex (V1) which form a characteristic honeycomb arrangement in layer 4A. It was hypothesized that if there were a low number of S-cone opponent projecting neurons in central vision then this would be seen as a reduction in afferents in foveal layer 4A. Recent studies have shown that the vesicular glutamate transporter 2 (VGlut2) is a marker for thalamic afferent terminals in cortex. The distribution of VGlut2-immunoreactive (-ir) terminals was studied in the foveal and perifoveal representation of V1. It was found that there was a substantial reduction in the terminal density in the foveal representation: the density was 5–6 times lower in the foveal V1 than in regions representing perifoveal eccentricities of 1°–2° and beyond. These findings may provide the cortical substrate of foveal tritanopia, the reduced blue perceptual ability for small fields in the center of gaze.
KW - Macaque
KW - S-cones
KW - Thalamic afferents
KW - Vesicular glutamate transporter
KW - Visual cortex
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U2 - 10.1007/s00429-014-0826-5
DO - 10.1007/s00429-014-0826-5
M3 - Article
C2 - 25009312
AN - SCOPUS:84940594039
SN - 1863-2653
VL - 220
SP - 2783
EP - 2796
JO - Brain Structure and Function
JF - Brain Structure and Function
IS - 5
ER -