Spatial Resolution and Contrast Sensitivity of Single Neurons in Area 19 of Split-chiasm Cats: A Comparison With Primary Visual Cortex

1997 ◽  
Vol 9 (9) ◽  
pp. 1929-1939 ◽  
Author(s):  
Eric Tardif ◽  
Louis Richer ◽  
André Bergeron ◽  
Franco Lepore ◽  
Jean-Paul Guillemot
Keyword(s):  
Visual Cortex ◽  
Contrast Sensitivity ◽  
Primary Visual Cortex ◽  
Spatial Resolution ◽  
Single Neurons ◽  
Area 19

scholarly journals Cortical reorganization of the visual system in post-stroke hemianopia studied with fMRI

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 334-334
Author(s):  
Gereon Nelles ◽  
Guido Widmann ◽  
Joachim Esser ◽  
Anette Meistrowitz ◽  
Johannes Weber ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual System ◽  
Primary Visual Cortex ◽  
Visual Stimuli ◽  
Checkerboard Pattern ◽  
Partial Recovery ◽  
Area 18 ◽  
Area 19 ◽  
Stimulation Of

102 Introduction: Restitution of unilateral visual field defects following occipital cortex lesions occurs rarely. Partial recovery, however, can be observed in patients with incomplete lesion of the visual cortex. Our objective was to study the neuroplastic changes in the visual system that underlie such recovery. Methods and Results: Six patients with a left PCA-territory cortical stroke and 6 healthy control subjects were studied during rest and during visual stimulation using a 1.5 T fMRI with a 40 mT gradient. Visual stimuli were projected with a laptop computer onto a 154 x 115 cm screen, placed 90 cm in front of the gantry. Subjects were asked to fixate a red point in the center of the screen during both conditions. During stimulation, a black-and-white checkerboard pattern reversal was presented in each hemifield. For each side, 120 volumes of 48 contiguous axial fMRI images were obtained during rest and during hemifield stimulation in alternating order (60 volumes for each condition). Significant differences of rCBF between stimulation and rest were assessed as group analyses using statistical parametric mapping (SPM 99; p<0.01, corrected for multiple comparison). In controls, strong increases of rCBF (Z=7.6) occurred in the contralateral primary visual cortex V1 (area 17) and in V3a (area 18) and V5 (area 19). No differences were found between the right and left side in controls. During stimulation of the unaffected (left) visual field in hemianopic patients, activation occurred in contralateral V1, but the strongest increases of rCBF (Z>10) were seen in contralateral V3a (area 18) and V5 (area 19). During stimulation of the hemianopic (right) visual field, no activation was found in the primary visual cortex of either hemisphere. The most significant activation (Z=9.2) was seen in the ipsilateral V3a and V5 areas, and contralateral (left) V3a. Conclusions: Partial recovery from hemianopia is associated with strong ipsilateral activation of the visual system. Processing of visual stimuli in the hemianopic side spares the primary visual cortex and may involve recruitment of neurons in ipsilateral (contralesional) areas V3a and V5.

scholarly journals Basal forebrain activation controls contrast sensitivity in primary visual cortex

2013 ◽  
Vol 14 (1) ◽  
pp. 55 ◽  
Author(s):  
Anwesha Bhattacharyya ◽  
Julia Veit ◽  
Robert Kretz ◽  
Igor Bondar ◽  
Gregor Rainer
Keyword(s):  
Visual Cortex ◽  
Contrast Sensitivity ◽  
Primary Visual Cortex ◽  
Basal Forebrain

Activation of metabotropic glutamate receptors has different effects in different layers of cat visual cortex

1997 ◽  
Vol 14 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Silvia N.M. Reid ◽  
Nigel W. Daw
Keyword(s):  
Visual Cortex ◽  
Dicarboxylic Acid ◽  
Glutamate Receptors ◽  
Spontaneous Activity ◽  
Primary Visual Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Visual Response ◽  
Single Neurons ◽  
Metabotropic Glutamate ◽  
Cat Visual Cortex

AbstractSingle neurons were recorded in cat primary visual cortex, and the effect of iontophoresis of the metabotropic glutamate agonist 1S,3R-aminocyclopentane-1.3-dicarboxylic acid (ACPD) was observed. In nearly all cases (41/43), ACPD reduced the visual response. In some cases ACPD also reduced spontaneous activity (24/43), and in other cases ACPD increased spontaneous activity (18/43). Increases were generally seen in infragranular layers (V and VI), and decreases in supragranular layers (II and III). The reduction in the visual response was also largest in supragranular layers. We conclude that activation of metabotropic glutamate receptors has both facilitatory and depressive effects in visual cortex, and the effect depends on the layer of the cell recorded.

Receptive Field Properties of Single Neurons in Rat Primary Visual Cortex

1999 ◽  
Vol 82 (1) ◽  
pp. 301-311 ◽  
Author(s):  
Sergej V. Girman ◽  
Yves Sauvé ◽  
Raymond D. Lund
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Receptive Fields ◽  
Stimulus Presentation ◽  
Cell Types ◽  
Bimodal Distribution ◽  
Form Perception ◽  
Uniform Field ◽  
Response Modulation ◽  
Single Neurons

The rat is used widely to study various aspects of vision including developmental events and numerous pathologies, but surprisingly little is known about the functional properties of single neurons in the rat primary visual cortex (V1). These were investigated in the anesthetized (Hypnorm-Hypnovel), paralyzed animal by presenting gratings of different orientations, spatial and temporal frequencies, dimensions, and contrasts. Stimulus presentation and data collection were automated. Most neurons (190/205) showed sharply tuned (≤30° bandwidth at half height) orientation selectivity with a bias for horizontal stimuli (31%). Analysis of response modulation of oriented cells showed a bimodal distribution consistent with the distinction between simple and complex cell types. Orientation specific interactions occurred between the center and the periphery of receptive fields, usually resulting in strong inhibition to center stimulation when both stimuli had the same orientation. There was no evidence for orientation columns nor for orderly change in optimal orientation with tangential tracks through V1. Responses were elicited by spatial frequencies ranging from zero (no grating) to 1.2 cycle/degree (c/°), peaking at 0.1 c/°, and with a modal cutoff of 0.6 c/°. Half of the neurons responded optimally to drifting gratings rather than flashing uniform field stimuli. Directional preference was seen for 59% of oriented units at all depths in the cortex. Optimal stimuli velocities varied from 10 to 250°/s. Some units, mainly confined to layer 4, responded to velocities as high as 700°/s. Response versus contrast curves (best fit with Naka-Rushton) varied from nearly linear to extremely steep (mean contrast semisaturation 50% and threshold 6%). There was a trend for cells from superficial layers to be more selective to different stimulus parameters than deeper layers cells. We conclude that neurons in rat V1 have complex and diverse visual properties, necessary for precise visual form perception with low spatial resolution.

scholarly journals Response Properties of Local Field Potentials and Neighboring Single Neurons in Awake Primary Visual Cortex

2012 ◽  
Vol 32 (33) ◽  
pp. 11396-11413 ◽  
Author(s):  
R. Lashgari ◽  
X. Li ◽  
Y. Chen ◽  
J. Kremkow ◽  
Y. Bereshpolova ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Local Field ◽  
Local Field Potentials ◽  
Field Potentials ◽  
Single Neurons ◽  
Response Properties

scholarly journals Distinct “driving” versus “modulatory” influences of different visual corticothalamic pathways

2021 ◽  
Author(s):  
Megan A. Kirchgessner ◽  
Alexis D. Franklin ◽  
Edward M. Callaway
Keyword(s):  
Cerebral Cortex ◽  
Visual Cortex ◽  
Superior Colliculus ◽  
Primary Visual Cortex ◽  
Cortical Layer ◽  
Single Neurons ◽  
Visual Responses ◽  
Thalamic Nuclei ◽  
Visual Thalamus

AbstractHigher-order (HO) thalamic nuclei interact extensively with the cerebral cortex and are innervated by excitatory corticothalamic (CT) populations in layers 5 and 6. While these distinct CT projections have long been thought to have different functional influences on the HO thalamus, this has never been directly tested. By optogenetically inactivating different CT populations in the primary visual cortex (V1) of awake mice, we demonstrate that layer 5, but not layer 6, CT projections drive visual responses in the HO visual pulvinar, even while both pathways provide retinotopic, baseline excitation to their thalamic targets. Inactivating the superior colliculus also suppressed visual responses in the pulvinar, demonstrating that cortical layer 5 and subcortical inputs both contribute to HO visual thalamic activity - even at the level of putative single neurons. Altogether, these results indicate a functional division of driver and modulator CT pathways from V1 to the visual thalamus in vivo.

Adaptation to Contingencies in Macaque Primary Visual Cortex

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 106-106
Author(s):  
M Carandini ◽  
H B Barlow ◽  
A B Poirson ◽  
L P O'Keefe ◽  
J A Movshon
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Primary Visual Cortex ◽  
Compound Stimulus ◽  
Visual Stimuli ◽  
The Other ◽  
Single Neurons ◽  
Optimal Orientation ◽  
The Individual

We tested the hypothesis that neurons in the primary visual cortex adapt selectively to contingencies in the attributes of visual stimuli. We recorded from single neurons in macaque V1 and measured the effects of adaptation either to the sum of two gratings (compound stimulus) or to the individual gratings. According to our hypothesis, there would be a component of adaptation that is specific to the compound stimulus. We performed two sets of experiments. In the first set one grating had optimal orientation and the other was orthogonal to it. In the second set the gratings were parallel, differed in spatial frequency, and were both effective in driving the cell. The first set of experiments, but not the second, provided evidence in favour of our hypothesis. In most cells tested with orthogonal gratings, adaptation to the compound stimulus reduced the responses to the compound stimulus more than the responses to the preferred grating. In addition, in most of these experiments the responses to the compound stimulus were reduced more by adaptation to the compound stimulus than by adaptation to the individual gratings. This suggests that a component of adaptation in the experiments with orthogonal gratings was specific to (and caused by) the contingent presence of the two gratings in the compound stimulus.

scholarly journals Color and orientation are jointly coded and spatially organized in primate primary visual cortex

Science ◽  
2019 ◽  
Vol 364 (6447) ◽  
pp. 1275-1279 ◽  
Author(s):  
Anupam K. Garg ◽  
Peichao Li ◽  
Mohammad S. Rashid ◽  
Edward M. Callaway
Keyword(s):  
Visual Cortex ◽  
Single Cell ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Calcium Imaging ◽  
Stimulus Space ◽  
Single Neurons ◽  
V1 Neurons ◽  
Two Photon ◽  
Rigorous Testing

Previous studies support the textbook model that shape and color are extracted by distinct neurons in primate primary visual cortex (V1). However, rigorous testing of this model requires sampling a larger stimulus space than previously possible. We used stable GCaMP6f expression and two-photon calcium imaging to probe a very large spatial and chromatic visual stimulus space and map functional microarchitecture of thousands of neurons with single-cell resolution. Notable proportions of V1 neurons strongly preferred equiluminant color over achromatic stimuli and were also orientation selective, indicating that orientation and color in V1 are mutually processed by overlapping circuits. Single neurons could precisely and unambiguously code for both color and orientation. Further analyses revealed systematic spatial relationships between color tuning, orientation selectivity, and cytochrome oxidase histology.

scholarly journals Enhanced Spatial Resolution During Locomotion and Heightened Attention in Mouse Primary Visual Cortex

2016 ◽  
Vol 36 (24) ◽  
pp. 6382-6392 ◽  
Author(s):  
Patrick J. Mineault ◽  
Elaine Tring ◽  
Joshua T. Trachtenberg ◽  
Dario L. Ringach
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Spatial Resolution
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