An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected.
The tracts between cortical areas are conceived as playing a central role in cortical information processing, but their actual numbers have never been determined in humans. Here, we estimate the absolute number of axons linking cortical areas from a whole-cortex diffusion MRI (dMRI) connectome, cali...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2022-03-01
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| Series: | PLoS Biology |
| Online Access: | https://doi.org/10.1371/journal.pbio.3001575 |
| _version_ | 1811257784094687232 |
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| author | Burke Q Rosen Eric Halgren |
| author_facet | Burke Q Rosen Eric Halgren |
| author_sort | Burke Q Rosen |
| collection | DOAJ |
| description | The tracts between cortical areas are conceived as playing a central role in cortical information processing, but their actual numbers have never been determined in humans. Here, we estimate the absolute number of axons linking cortical areas from a whole-cortex diffusion MRI (dMRI) connectome, calibrated using the histologically measured callosal fiber density. Median connectivity is estimated as approximately 6,200 axons between cortical areas within hemisphere and approximately 1,300 axons interhemispherically, with axons connecting functionally related areas surprisingly sparse. For example, we estimate that <5% of the axons in the trunk of the arcuate and superior longitudinal fasciculi connect Wernicke's and Broca's areas. These results suggest that detailed information is transmitted between cortical areas either via linkage of the dense local connections or via rare, extraordinarily privileged long-range connections. |
| first_indexed | 2024-04-12T18:02:53Z |
| format | Article |
| id | doaj.art-004dc1f4118d48838d1203ae26de2b13 |
| institution | Directory Open Access Journal |
| issn | 1544-9173 1545-7885 |
| language | English |
| last_indexed | 2024-04-12T18:02:53Z |
| publishDate | 2022-03-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Biology |
| spelling | doaj.art-004dc1f4118d48838d1203ae26de2b132022-12-22T03:22:04ZengPublic Library of Science (PLoS)PLoS Biology1544-91731545-78852022-03-01203e300157510.1371/journal.pbio.3001575An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected.Burke Q RosenEric HalgrenThe tracts between cortical areas are conceived as playing a central role in cortical information processing, but their actual numbers have never been determined in humans. Here, we estimate the absolute number of axons linking cortical areas from a whole-cortex diffusion MRI (dMRI) connectome, calibrated using the histologically measured callosal fiber density. Median connectivity is estimated as approximately 6,200 axons between cortical areas within hemisphere and approximately 1,300 axons interhemispherically, with axons connecting functionally related areas surprisingly sparse. For example, we estimate that <5% of the axons in the trunk of the arcuate and superior longitudinal fasciculi connect Wernicke's and Broca's areas. These results suggest that detailed information is transmitted between cortical areas either via linkage of the dense local connections or via rare, extraordinarily privileged long-range connections.https://doi.org/10.1371/journal.pbio.3001575 |
| spellingShingle | Burke Q Rosen Eric Halgren An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected. PLoS Biology |
| title | An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected. |
| title_full | An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected. |
| title_fullStr | An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected. |
| title_full_unstemmed | An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected. |
| title_short | An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected. |
| title_sort | estimation of the absolute number of axons indicates that human cortical areas are sparsely connected |
| url | https://doi.org/10.1371/journal.pbio.3001575 |
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