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In Vivo Mapping of Cortical Columnar Networks in the Monkey with Focal Electrical and Optical Stimulation.

Roe AW, Chernov MM, Friedman RM, Chen G - Front Neuroanat (2015)

Bottom Line: However, there has been little emphasis on understanding connection patterns between functionally specific cortical columns.These new approaches, when applied systematically on a large scale, will elucidate functionally specific intra-areal and inter-areal network connection patterns.Such functionally specific network data can provide accurate views of brain network topology.

View Article: PubMed Central - PubMed

Affiliation: Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University Hangzhou, China.

ABSTRACT
There are currently largescale efforts to understand the brain as a connection machine. However, there has been little emphasis on understanding connection patterns between functionally specific cortical columns. Here, we review development and application of focal electrical and optical stimulation methods combined with optical imaging and fMRI mapping in the non-human primate. These new approaches, when applied systematically on a large scale, will elucidate functionally specific intra-areal and inter-areal network connection patterns. Such functionally specific network data can provide accurate views of brain network topology.

No MeSH data available.


Optical image of color response seen through an implanted cranial window over macaque monkey visual cortex (areas V1, V2, and V4). Image obtained by subtracting response to red-green isoluminant grating minus achromatic grating. Arrays of blobs in V1 and thin stripes in V2 (red arrows) reveal size of columnar networks (200 μm). Sizes of voxels used in human fMRI (yellow 3 mm and white 1 mm boxes) include many functional columns; functional resting state connections between these columns (bidirectional arrows) are therefore based on averaged signals and not functionally specific. Small red arrows: two visible thin (color) stripes in V2. ls: lunate sulcus. Dotted white line: V1/V2 border. Scale bar: 10 mm. (Image adapted from Lu and Roe, 2008).
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Figure 2: Optical image of color response seen through an implanted cranial window over macaque monkey visual cortex (areas V1, V2, and V4). Image obtained by subtracting response to red-green isoluminant grating minus achromatic grating. Arrays of blobs in V1 and thin stripes in V2 (red arrows) reveal size of columnar networks (200 μm). Sizes of voxels used in human fMRI (yellow 3 mm and white 1 mm boxes) include many functional columns; functional resting state connections between these columns (bidirectional arrows) are therefore based on averaged signals and not functionally specific. Small red arrows: two visible thin (color) stripes in V2. ls: lunate sulcus. Dotted white line: V1/V2 border. Scale bar: 10 mm. (Image adapted from Lu and Roe, 2008).

Mentions: Current human connectomes (based on fMRI study) lack the spatial resolution for examining connection patterns at the columnar scale and therefore lack functional specificity inherent in columnar organization. Individual voxels in these studies represent averages of multiple functional columns (Figure 2, yellow box represents 3 mm voxel, white box represents 1 mm voxel); networks of voxels (Figure 2, yellow and white bidirectional arrows) therefore represent connections between averages of multiple functional networks. Due to the differential connectivity patterns of individual columns (e.g., color blobs to thin stripes vs. orientation columns to pale/thick stripes, Livingstone and Hubel, 1984; Roe and Ts’o, 1999, 2015; Sincich et al., 2010; Federer et al., 2013), such averages can lead to inaccurate and misleading conclusions about cortical networks.


In Vivo Mapping of Cortical Columnar Networks in the Monkey with Focal Electrical and Optical Stimulation.

Roe AW, Chernov MM, Friedman RM, Chen G - Front Neuroanat (2015)

Optical image of color response seen through an implanted cranial window over macaque monkey visual cortex (areas V1, V2, and V4). Image obtained by subtracting response to red-green isoluminant grating minus achromatic grating. Arrays of blobs in V1 and thin stripes in V2 (red arrows) reveal size of columnar networks (200 μm). Sizes of voxels used in human fMRI (yellow 3 mm and white 1 mm boxes) include many functional columns; functional resting state connections between these columns (bidirectional arrows) are therefore based on averaged signals and not functionally specific. Small red arrows: two visible thin (color) stripes in V2. ls: lunate sulcus. Dotted white line: V1/V2 border. Scale bar: 10 mm. (Image adapted from Lu and Roe, 2008).
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Related In: Results  -  Collection

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Figure 2: Optical image of color response seen through an implanted cranial window over macaque monkey visual cortex (areas V1, V2, and V4). Image obtained by subtracting response to red-green isoluminant grating minus achromatic grating. Arrays of blobs in V1 and thin stripes in V2 (red arrows) reveal size of columnar networks (200 μm). Sizes of voxels used in human fMRI (yellow 3 mm and white 1 mm boxes) include many functional columns; functional resting state connections between these columns (bidirectional arrows) are therefore based on averaged signals and not functionally specific. Small red arrows: two visible thin (color) stripes in V2. ls: lunate sulcus. Dotted white line: V1/V2 border. Scale bar: 10 mm. (Image adapted from Lu and Roe, 2008).
Mentions: Current human connectomes (based on fMRI study) lack the spatial resolution for examining connection patterns at the columnar scale and therefore lack functional specificity inherent in columnar organization. Individual voxels in these studies represent averages of multiple functional columns (Figure 2, yellow box represents 3 mm voxel, white box represents 1 mm voxel); networks of voxels (Figure 2, yellow and white bidirectional arrows) therefore represent connections between averages of multiple functional networks. Due to the differential connectivity patterns of individual columns (e.g., color blobs to thin stripes vs. orientation columns to pale/thick stripes, Livingstone and Hubel, 1984; Roe and Ts’o, 1999, 2015; Sincich et al., 2010; Federer et al., 2013), such averages can lead to inaccurate and misleading conclusions about cortical networks.

Bottom Line: However, there has been little emphasis on understanding connection patterns between functionally specific cortical columns.These new approaches, when applied systematically on a large scale, will elucidate functionally specific intra-areal and inter-areal network connection patterns.Such functionally specific network data can provide accurate views of brain network topology.

View Article: PubMed Central - PubMed

Affiliation: Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University Hangzhou, China.

ABSTRACT
There are currently largescale efforts to understand the brain as a connection machine. However, there has been little emphasis on understanding connection patterns between functionally specific cortical columns. Here, we review development and application of focal electrical and optical stimulation methods combined with optical imaging and fMRI mapping in the non-human primate. These new approaches, when applied systematically on a large scale, will elucidate functionally specific intra-areal and inter-areal network connection patterns. Such functionally specific network data can provide accurate views of brain network topology.

No MeSH data available.