In:
eLife, eLife Sciences Publications, Ltd, Vol. 5 ( 2016-08-09)
Abstract:
The outer layer of the mammalian brain the cerebral cortex plays a key role in memory, attention, awareness and thought. While rodents have a smooth cortical surface, the cortex of larger mammals such as primates is organized into folds and furrows. These folds increase the amount of cortex that can fit inside the confines of the skull, and are thought to have allowed the evolution of more advanced thought processes. Mutations in various genes are likely to have contributed to the expansion and folding of the cortex. These mutations may not always have involved changes in the instructions encoded within the genes, but might instead have involved changes in the number of copies of a gene. One plausible candidate gene is TBC1D3, which is only found in the great apes and is active in the cortex. The chimpanzee genome contains a single copy of TBC1D3 whereas the human genome contains multiple copies. Ju, Hou et al. have now shown that introducing the TBC1D3 gene into mouse embryos triggers changes in the embryonic cortex. Specifically, this gene increases the number of a type of cell called the outer radial glial cell in the cortex. These cells give rise to new neurons, and are usually rare in mice but abundant in the brains of animals with a folded cortex. Additional experiments using samples of human brain tissue confirmed that TBC1D3 is required for the outer radial glial cells to form. The samples were collected from miscarried fetuses with the informed consent of the patients and following approved protocols and ethical guidelines. Finally, introducing the TBC1D3 gene into the mouse genome also gave rise to animals with a folded cortex, rather than their usual smooth brain surface. Further work is now required to identify how TBC1D3 helps to generate outer radial glial cells, and to work out how these cells cause the cortex to expand. Testing the behavior of mice with the TBC1D3 gene could also uncover the links between cortical folding and thought processes.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.18197.001
DOI:
10.7554/eLife.18197.002
DOI:
10.7554/eLife.18197.003
DOI:
10.7554/eLife.18197.004
DOI:
10.7554/eLife.18197.005
DOI:
10.7554/eLife.18197.006
DOI:
10.7554/eLife.18197.007
DOI:
10.7554/eLife.18197.008
DOI:
10.7554/eLife.18197.009
DOI:
10.7554/eLife.18197.010
DOI:
10.7554/eLife.18197.011
DOI:
10.7554/eLife.18197.012
DOI:
10.7554/eLife.18197.013
DOI:
10.7554/eLife.18197.014
DOI:
10.7554/eLife.18197.015
DOI:
10.7554/eLife.18197.016
DOI:
10.7554/eLife.18197.017
DOI:
10.7554/eLife.18197.018
DOI:
10.7554/eLife.18197.019
DOI:
10.7554/eLife.18197.020
DOI:
10.7554/eLife.18197.021
DOI:
10.7554/eLife.18197.022
DOI:
10.7554/eLife.18197.023
DOI:
10.7554/eLife.18197.024
DOI:
10.7554/eLife.18197.025
DOI:
10.7554/eLife.18197.026
DOI:
10.7554/eLife.18197.027
DOI:
10.7554/eLife.18197.028
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2016
detail.hit.zdb_id:
2687154-3
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