A direct projection from area V1 to area V3A of rhesus monkey visual cortex

1980 ◽  
Vol 207 (1169) ◽  
pp. 499-506 ◽  

Small cortical lesions were made in regions of the primary visual cortex (V1) representing different retinal eccentricities. It was found that, whereas all parts of V1 project to visual areas V2, V3 and the motion area of the superior temporal sulcus, only parts of V1 representing peripheral eccentricities (in excess of 30°) project directly to visual area V3A.

1976 ◽  
Vol 193 (1111) ◽  
pp. 199-207 ◽  

When small electrolytic lesions area made in area 18 and [ 3 H]proline is injected into area 17 of the same side, the inputs to the visual area of the superior temporal sulcus, from these two areas can he mapped separately and independently in the same animal. By using this approach, it was found that both area 17 and area 18 project to the same small region in the posterior bank of the superior temporal sulcus. We conclude that the latter area receives an overlapping input from area 17 and from area 18.


1977 ◽  
Vol 199 (1137) ◽  
pp. 588-588

Proc. R. Soc. Loud . B 197, 195-223 (1977) Colour coding in the superior temporal sulcus of rhesus monkey visual cortex By S. M. Zeki Page 211, paragraph 2, penultimate line: ‘. . .shown to the right of figure 13. . . ’ should read ‘. . .shown to the right of figure 14. . . ’. Page 215, description of figure 11: ‘The response of cell 7 of figure 5’ should read ‘The response of cell 7 of figure 9’. Plate 4 (facing page 216). ( a ) Description of plate 4, line 3: ‘reconstructed in figure 11’ should read ‘reconstructed in figure 12’. In the last line, ‘figure 21’ should be deleted and ‘plate 4’ should read ‘plate 5’. ( b ) Description of figure 12, fifth line: ‘ . . .is plotted in figure 14’ should read ‘. . .is plotted in figure 15’. Plate 5 (facing page 217), description, line 1: ‘shown in plate 3’ should read ‘shown in plate 4’. Page 218, description of figure 15: ‘figure 11’ should read ‘figure 12’. Page 220, fifth line from bottom: ‘(see figure 5 and Zeki 1975)’ should read ‘(see figure 9 and Zeki 1975)'.


2019 ◽  
Author(s):  
Kevin A. Murgas ◽  
Ashley M. Wilson ◽  
Valerie Michael ◽  
Lindsey L. Glickfeld

AbstractNeurons in the visual system integrate over a wide range of spatial scales. This diversity is thought to enable both local and global computations. To understand how spatial information is encoded across the mouse visual system, we use two-photon imaging to measure receptive fields in primary visual cortex (V1) and three downstream higher visual areas (HVAs): LM (lateromedial), AL (anterolateral) and PM (posteromedial). We find significantly larger receptive field sizes and less surround suppression in PM than in V1 or the other HVAs. Unlike other visual features studied in this system, specialization of spatial integration in PM cannot be explained by specific projections from V1 to the HVAs. Instead, our data suggests that distinct connectivity within PM may support the area’s unique ability to encode global features of the visual scene, whereas V1, LM and AL may be more specialized for processing local features.


2012 ◽  
Vol 108 (9) ◽  
pp. 2363-2372 ◽  
Author(s):  
Mark McAvoy ◽  
Linda Larson-Prior ◽  
Marek Ludwikow ◽  
Dongyang Zhang ◽  
Abraham Z. Snyder ◽  
...  

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.


Glia ◽  
2008 ◽  
Vol 56 (11) ◽  
pp. 1151-1161 ◽  
Author(s):  
Alan Peters ◽  
Ameigh Verderosa ◽  
Claire Sethares

2017 ◽  
Author(s):  
Amelia J. Christensen ◽  
Jonathan W. Pillow

Running profoundly alters stimulus-response properties in mouse primary visual cortex (V1), but its effects in higher-order visual cortex remain unknown. Here we systematically investigated how locomotion modulates visual responses across six visual areas and three cortical layers using a massive dataset from the Allen Brain Institute. Although running has been shown to increase firing in V1, we found that it suppressed firing in higher-order visual areas. Despite this reduction in gain, visual responses during running could be decoded more accurately than visual responses during stationary periods. We show that this effect was not attributable to changes in noise correlations, and propose that it instead arises from increased reliability of single neuron responses during running.


2019 ◽  
Author(s):  
E. Mika Diamanti ◽  
Charu Bai Reddy ◽  
Sylvia Schröder ◽  
Tomaso Muzzu ◽  
Kenneth D. Harris ◽  
...  

During navigation, the visual responses of neurons in primary visual cortex (V1) are modulated by the animal’s spatial position. Here we show that this spatial modulation is similarly present across multiple higher visual areas but largely absent in the main thalamic pathway into V1. Similar to hippocampus, spatial modulation in visual cortex strengthens with experience and requires engagement in active behavior. Active navigation in a familiar environment, therefore, determines spatial modulation of visual signals starting in the cortex.


2021 ◽  
Author(s):  
Yulia Revina ◽  
Lucy S Petro ◽  
Cristina B Denk-Florea ◽  
Isa S Rao ◽  
Lars Muckli

The majority of synaptic inputs to the primary visual cortex (V1) are non-feedforward, instead originating from local and anatomical feedback connections. Animal electrophysiology experiments show that feedback signals originating from higher visual areas with larger receptive fields modulate the surround receptive fields of V1 neurons. Theories of cortical processing propose various roles for feedback and feedforward processing, but systematically investigating their independent contributions to cortical processing is challenging because feedback and feedforward processes coexist even in single neurons. Capitalising on the larger receptive fields of higher visual areas compared to primary visual cortex (V1), we used an occlusion paradigm that isolates top-down influences from feedforward processing. We utilised functional magnetic resonance imaging (fMRI) and multi-voxel pattern analysis methods in humans viewing natural scene images. We parametrically measured how the availability of contextual information determines the presence of detectable feedback information in non-stimulated V1, and how feedback information interacts with feedforward processing. We show that increasing the visibility of the contextual surround increases scene-specific feedback information, and that this contextual feedback enhances feedforward information. Our findings are in line with theories that cortical feedback signals transmit internal models of predicted inputs.


1994 ◽  
Vol 72 (1) ◽  
pp. 163-168 ◽  
Author(s):  
H. Sato ◽  
N. Katsuyama ◽  
H. Tamura ◽  
Y. Hata ◽  
T. Tsumoto

1. Input mechanisms of 21 color-selective cells in cytochrome oxidase-rich blobs in layer II/III of the anesthetized and paralyzed monkey primary visual cortex were studied by an iontophoretic administration of the GABAergic receptor antagonist bicuculline methiodide (BMI). 2. Color-selective blob cells become responsive to originally nonresponsive colors of stimuli or brightness contrast stimuli during removal of intracortical inhibition. 3. The magnitudes of the cells' responses to color stimuli during BMI administration were larger than the expected value of response calculated from the previously reported color tuning of color-selective geniculate cells and emission spectra of color stimulus. 4. These results suggest that color-selective blob cells receive a convergence of different types of chromatic inputs and that intracortical inhibition confers selectivity for a given color on them.


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