Brain circuitry shaped by competition for space as well as genetics

September 29, 2020

Complex brain circuits in rodents can organise themselves with genetics playing only a secondary role, according to a new computer modelling study published today in eLife.

The findings help answer a key question about how the brain wires itself during development. They suggest that simple interactions between nerve cells contribute to the development of complex brain circuits, so that a precise genetic blueprint for brain circuitry is unnecessary. This discovery may help scientists better understand disorders that affect brain development and inform new ways to treat conditions that disrupt brain circuits.

The circuits that help rodents process sensory information collected by their whiskers are a great example of the complexity of brain wiring. These circuits are organised into cylindrical clusters or 'whisker barrels' that closely match the pattern of whiskers on the animal's face.

"The brain cells within one whisker barrel become active when its corresponding whisker is touched," explains lead author Sebastian James, Research Associate at the Department of Psychology, University of Sheffield, UK. "This precise mapping between the individual whisker and its brain representation makes the whisker-barrel system ideal for studying brain wiring."

James and his colleagues used computer modelling to determine if this pattern of brain wiring could emerge without a precise genetic blueprint. Their simulations showed that, in the cramped quarters of the developing rodent brain, strong competition for space between nerve fibers originating from different whiskers can cause them to concentrate into whisker-specific clusters. The arrangement of these clusters to form a map of the whiskers is assisted by simple patterns of gene expression in the brain tissue.

The team also tested their model by seeing if it could recreate the results of experiments that track the effects of a rat losing a whisker on its brain development. "Our simulations demonstrated that the model can be used to accurately test how factors inside and outside of the brain can contribute to the development of cortical fields," says co-author Leah Krubitzer, Professor of Psychology at the University of California, Davis, US.

The authors suggest that this and similar computational models could be adapted to study the development of larger, more complex brains, including those of humans.

"Many of the basic mechanisms of development in the rodent barrel cortex are thought to translate to development in the rest of cortex, and may help inform research into various neurodevelopmental disorders and recovery from brain injuries," concludes senior author Stuart Wilson, Lecturer in Cognitive Neuroscience at the University of Sheffield. "As well as reducing the number of animal experiments needed to understand cortical development, exploring the parameters of computational models like ours can offer new insights into how development and evolution interact to shape the brains of mammals, including ourselves."
-end-
Reference

The paper 'Modeling the emergence of whisker barrels' can be freely accessed online at https://doi.org/10.7554/eLife.55588. Contents, including text, figures and data, are free to reuse under a CC BY 4.0 license.

Media contact

Emily Packer, Media Relations Manager
eLife
e.packer@elifesciences.org
01223 855373

About eLife

eLife is a non-profit organisation created by funders and led by researchers. Our mission is to accelerate discovery by operating a platform for research communication that encourages and recognises the most responsible behaviours. We work across three major areas: publishing, technology and research culture. We aim to publish work of the highest standards and importance in all areas of biology and medicine, including Computational and Systems Biology and Developmental Biology, while exploring creative new ways to improve how research is assessed and published. We also invest in open-source technology innovation to modernise the infrastructure for science publishing and improve online tools for sharing, using and interacting with new results. eLife receives financial support and strategic guidance from the Howard Hughes Medical Institute, the Knut and Alice Wallenberg Foundation, the Max Planck Society and Wellcome. Learn more at https://elifesciences.org/about.

To read the latest Computational and Systems Biology research published in eLife, visit https://elifesciences.org/subjects/computational-systems-biology.

And for the latest in Developmental Biology, see https://elifesciences.org/subjects/developmental-biology.

eLife

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.