scholarly journals Functional-Specific Projections from V2 to V4 in Macaque Monkeys

2021 ◽  
Author(s):  
Chen Fang ◽  
Kun Yan ◽  
Chen Liang ◽  
Jiayu Wang ◽  
Xingya Cai ◽  
...  
Keyword(s):  
Cytochrome Oxidase ◽  
Functional Properties ◽  
Visual Processing ◽  
Fluorescent Tracers ◽  
Functional Specificity ◽  
Macaque Monkeys ◽  
Intrinsic Signal ◽  
Area V4 ◽  
Area V2 ◽  
Intrinsic Signal Optical Imaging

Abstract Previous studies have revealed modular projections from area V2 to area V4 in macaques. Specifically, V2 neurons in cytochrome oxidase (CO)-rich thin and CO-sparse pale stripes project to distinct regions in V4. However, how these modular projections relate to the functional subcompartments of V4 remains unclear. In this study, we injected retrograde fluorescent tracers into different functional domains (color, orientation, and direction) in V4 that were identified with intrinsic signal optical imaging. We examined the labeled neurons in area V2 and their locations with respect to the CO patterns. Covariation was observed between the functional properties of the V4 injection sites and the numbers of labeled neurons in particular CO stripes. This covariation indicates that the color domains in V4 mainly received inputs from V2 thin stripes, whereas V4 orientation domains received inputs from pale (major) and thick (minor) stripes. Although there are motion-sensitive domains in both V2 and V4, our results did not reveal a functional-specific feedforward projection between them. These results confirmed previous findings of modular projections from V2 to V4 and provided functional specificity for these anatomical projections. Together, these findings indicate that color and form remain separate in the ventral midlevel visual processing.

scholarly journals Functional Properties of Neurons in Macaque Area V3

1997 ◽  
Vol 77 (4) ◽  
pp. 1906-1923 ◽  
Author(s):  
Karl R. Gegenfurtner ◽  
Daniel C. Kiper ◽  
Jonathan B. Levitt
Keyword(s):  
Functional Properties ◽  
Visual Processing ◽  
Significant Proportion ◽  
Large Degree ◽  
Visual Signals ◽  
Motion Processing ◽  
Temporal Area ◽  
Area V2 ◽  
Layer 4 ◽  
Contrast Thresholds

Gegenfurtner, Karl R., Daniel C. Kiper, and Jonathan B. Levitt. Functional properties of neurons in macaque area V3. J. Neurophysiol. 77: 1906–1923, 1997. We investigated the functional properties of neurons in extrastriate area V3. V3 receives inputs from both magno- and parvocellular pathways and has prominent projections to both the middle temporal area (area MT) and V4. It may therefore represent an important site for integration and transformation of visual signals. We recorded the activity of single units representing the central 10° in anesthetized, paralyzed macaque monkeys. We measured each cell's spatial, temporal, chromatic, and motion properties with the use of a variety of stimuli. Results were compared with measurements made in V2 neurons at similar eccentricities. Similar to area V2, most of the neurons in our sample (80%) were orientation selective, and the distribution of orientation bandwidths was similar to that found in V2. Neurons in V3 preferred lower spatial and higher temporal frequencies than V2 neurons. Contrast thresholds of V3 neurons were extremely low. Achromatic contrast sensitivity was much higher than in V2, and similar to that found in MT. About 40% of all neurons showed strong directional selectivity. We did not find strongly directional cells in layer 4 of V3, the layer in which the bulk of V1 and V2 inputs terminate. This property seems to be developed within area V3. An analysis of the responses of directionally selective cells to plaid patterns showed that in area V3, as in MT and unlike in V1 and V2, there exist cells sensitive to the motion of the plaid pattern rather than to that of the components. The exact proportion of cells classified as being selective to color depended to a large degree on the experiment and on the criteria used for classification. With the use of the same conditions as in a previous study of V2 cells, we found as many (54%) color-selective cells as in V2 (50%). Furthermore, the responses of V3 cells to colored sinusoidal gratings were well described by a linear combination of cone inputs. The two subpopulations of cells responsive to color and to motion overlapped to a large extent, and we found a significant proportion of cells that gave reliable and directional responses to drifting isoluminant gratings. Our results show that there is a significant interaction between color and motion processing in area V3, and that V3 cells exhibit the more complex motion properties typically observed at later stages of visual processing.

Processing of color, form, and motion in macaque area V2

1996 ◽  
Vol 13 (1) ◽  
pp. 161-172 ◽  
Author(s):  
Karl R. Gegenfurtner ◽  
Daniel C. Kiper ◽  
Suzanne B. Fenstemaker
Keyword(s):  
Cytochrome Oxidase ◽  
Negative Correlation ◽  
Cortical Area ◽  
Stimulus Dimension ◽  
Anatomical Location ◽  
Invariant Representation ◽  
Macaque Monkeys ◽  
Area V2 ◽  
Color Selectivity ◽  
Color Form

AbstractWe investigated the representation of color in cortical area V2 of macaque monkeys, and the association of color with other stimulus attributes. We measured the selectivity of individual V2 neurons for color, motion, and form. Most neurons in V2 were orientation selective, about half of them were selective for color, and a minority of cells (about 20%) were selective for size or direction. We correlated these physiological measurements with the anatomical location of the cells with respect to the cytochrome oxidase (CO) compartments of area V2. There was a tendency for color-selective cells to be found more frequently in the thin stripes, but color-selective cells also occurred frequently in thick stripes and inter-stripes. We found no difference in the degree of color selectivity between the different CO compartments. Furthermore, there was no negative correlation between color selectivity and selectivity for other stimulus attributes. We found many cells capable of encoding information along more than one stimulus dimension, regardless of their location with respect to the CO compartments. We suggest that area V2 plays an important role in integrating information about color, motion, and form. By this integration of stimulus attributes a cue-invariant representation of the visual world might be achieved.

Projections from the cytochrome oxidase modules of visual area V2 to the ventral posterior area in the macaque

2004 ◽  
Vol 155 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Hiroyuki Nakamura ◽  
Wu Ri Le ◽  
Masumi Wakita ◽  
Akichika Mikami ◽  
Kazuo Itoh
Keyword(s):  
Cytochrome Oxidase ◽  
Visual Area ◽  
Area V2 ◽  
Posterior Area

scholarly journals Neuronal Responses in Visual Area V2 (V2) of Macaque Monkeys with Strabismic Amblyopia

2011 ◽  
Vol 21 (9) ◽  
pp. 2033-2045 ◽  
Author(s):  
H. Bi ◽  
B. Zhang ◽  
X. Tao ◽  
R. S. Harwerth ◽  
E. L. Smith ◽  
...  
Keyword(s):  
Visual Area ◽  
Neuronal Responses ◽  
Strabismic Amblyopia ◽  
Macaque Monkeys ◽  
Area V2

scholarly journals Functional neocortical microcircuitry demonstrated with intrinsic signal optical imaging in vitro

Neuroscience ◽  
1999 ◽  
Vol 95 (1) ◽  
pp. 51-62 ◽  
Author(s):  
A. Kohn ◽  
C. Metz ◽  
M. Quibrera ◽  
M.A. Tommerdahl ◽  
B.L. Whitsel
Keyword(s):  
Optical Imaging ◽  
Intrinsic Signal ◽  
Intrinsic Signal Optical Imaging

scholarly journals Hand placement near the visual stimulus improves orientation selectivity in V2 neurons

2015 ◽  
Vol 113 (7) ◽  
pp. 2859-2870 ◽  
Author(s):  
Carolyn J. Perry ◽  
Lauren E. Sergio ◽  
J. Douglas Crawford ◽  
Mazyar Fallah
Keyword(s):  
Visual Processing ◽  
Neuronal Response ◽  
Oculomotor System ◽  
Orientation Selectivity ◽  
Orientation Tuning ◽  
Area V2 ◽  
Visual Enhancement ◽  
Orthogonal Orientation ◽  
Psychophysical Studies ◽  
The Brain

Often, the brain receives more sensory input than it can process simultaneously. Spatial attention helps overcome this limitation by preferentially processing input from a behaviorally-relevant location. Recent neuropsychological and psychophysical studies suggest that attention is deployed to near-hand space much like how the oculomotor system can deploy attention to an upcoming gaze position. Here we provide the first neuronal evidence that the presence of a nearby hand enhances orientation selectivity in early visual processing area V2. When the hand was placed outside the receptive field, responses to the preferred orientation were significantly enhanced without a corresponding significant increase at the orthogonal orientation. Consequently, there was also a significant sharpening of orientation tuning. In addition, the presence of the hand reduced neuronal response variability. These results indicate that attention is automatically deployed to the space around a hand, improving orientation selectivity. Importantly, this appears to be optimal for motor control of the hand, as opposed to oculomotor mechanisms which enhance responses without sharpening orientation selectivity. Effector-based mechanisms for visual enhancement thus support not only the spatiotemporal dissociation of gaze and reach, but also the optimization of vision for their separate requirements for guiding movements.

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