scholarly journals Macular degeneration affects functional connectivity of primary visual cortex

2014 ◽  
Vol 14 (10) ◽  
pp. 956-956 ◽  
Author(s):  
K. Visscher ◽  
R. Nenert ◽  
D. DeCarlo ◽  
R. Chen ◽  
L. Ross
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Macular Degeneration ◽  
Primary Visual Cortex

scholarly journals Altered functional connectivity of primary visual cortex in late blindness

2018 ◽  
Vol Volume 14 ◽  
pp. 3317-3327 ◽  
Author(s):  
Zhi Wen ◽  
Fu-Qing Zhou ◽  
Xin Huang ◽  
Han Dong Dan ◽  
Bao-Jun Xie ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Primary Visual Cortex

scholarly journals Dissociated mean and functional connectivity BOLD signals in visual cortex during eyes closed and fixation

2012 ◽  
Vol 108 (9) ◽  
pp. 2363-2372 ◽  
Author(s):  
Mark McAvoy ◽  
Linda Larson-Prior ◽  
Marek Ludwikow ◽  
Dongyang Zhang ◽  
Abraham Z. Snyder ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Primary Visual Cortex ◽  
Blood Oxygen Level Dependent ◽  
Extrastriate Cortex ◽  
Connected Components ◽  
Bold Signal ◽  
Thalamic Nuclei ◽  
Eyes Closed ◽  
Visual Areas

We investigated the effects of resting state type on blood oxygen level-dependent (BOLD) signal and functional connectivity in two paradigms: participants either alternated between fixation and eyes closed or maintained fixation or eyes closed throughout each scan. The BOLD signal and functional connectivity of lower and higher tiers of the visual cortical hierarchy were found to be differentially modulated during eyes closed versus fixation. Fixation was associated with greater mean BOLD signals in primary visual cortex and lower mean BOLD signals in extrastriate visual areas than periods of eyes closed. In addition, analysis of thalamocortical functional connectivity during scans in which participants maintained fixation showed synchronized BOLD fluctuations between those thalamic nuclei whose mean BOLD signal was systematically modulated during alternating epochs of eyes closed and fixation, primary visual cortex and the attention network, while during eyes closed negatively correlated fluctuations were seen between the same thalamic nuclei and extrastriate visual areas. Finally, in all visual areas the amplitude of spontaneous BOLD fluctuations was greater during eyes closed than during fixation. The dissociation between early and late tiers of visual cortex, which characterizes both mean and functionally connected components of the BOLD signal, may depend on the reorganization of thalamocortical networks. Since dissociated changes in local blood flow also characterize transitions between different stages of sleep and wakefulness (Braun AR, Balkin TJ, Wesenten NJ, Gwadry F, Carson RE, Varga M, Baldwin P, Belenky G, Herscovitch P. Science 279: 91–95, 1998), our results suggest that dissociated endogenous neural activity in primary and extrastriate cortex may represent a general aspect of brain function.

Antidromic latency of magnocellular, parvocellular, and koniocellular (Blue-ON) geniculocortical relay cells in marmosets

2014 ◽  
Vol 31 (3) ◽  
pp. 263-273 ◽  
Author(s):  
SOON KEEN CHEONG ◽  
ALEXANDER NICOLAAS JOHANNES PIETERSEN
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Primary Visual Cortex ◽  
Visual Stimulation ◽  
Blue Color ◽  
High Contrast ◽  
Response Latencies ◽  
Bon Cells ◽  
P Cells ◽  
Parallel Visual Pathways

AbstractWe studied the functional connectivity of cells in the lateral geniculate nucleus (LGN) with the primary visual cortex (V1) in anesthetized marmosets (Callithrix jacchus). The LGN sends signals to V1 along parallel visual pathways called parvocellular (P), magnocellular (M), and koniocellular (K). To better understand how these pathways provide inputs to V1, we antidromically activated relay cells in the LGN by electrically stimulating V1 and measuring the conduction latencies of P (n = 7), M (n = 14), and the “Blue-ON” (n = 5) subgroup of K cells (K-BON cells). We found that the antidromic latencies of K-BON cells were similar to those of P cells. We also measured the response latencies to high contrast visual stimuli for a subset of cells. We found the LGN cells that have the shortest latency of response to visual stimulation also have the shortest antidromic latencies. We conclude that Blue color signals are transmitted directly to V1 from the LGN by K-BON cells.

scholarly journals Altered functional connectivity of primary visual cortex in early blindness

2008 ◽  
Vol 29 (5) ◽  
pp. 533-543 ◽  
Author(s):  
Chunshui Yu ◽  
Yong Liu ◽  
Jun Li ◽  
Yuan Zhou ◽  
Kun Wang ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Primary Visual Cortex ◽  
Early Blindness
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