Rewiring the mammalian brain -- neurons make fickle friends

August 8, 2006
Brain

A new discovery from the Brain Mind Institute of the EPFL (Ecole Polytechnique Federale de Lausanne) shows that the brain rewires itself following an experience. The research further shows that this process of creation, testing, and reconfiguring of brain circuits takes place on a scale of just hours, suggesting that the brain is evolving considerably even during the course of a single day.

Scientists know that the strength of the connections between neurons changes to shape memories. They also know that the developing brain has a high level of plasticity as neurons forge connections with other neurons.

This new research, published in the August 7, 2006 early online edition of the Proceedings of the National Academy of Sciences, goes further, investigating how neurons choose their connections with neighboring neurons. Researchers Henry Markram and Jean-Vincent Le Bé found that connections between neurons switch rapidly on and off, leading to a form of adaptive rewiring in which the brain is engaged in a continuous process of changing, strengthening and pruning its circuitry.

Studying neuron clusters from the neocortex of neonatal rats, Markram and Le Bé found that instead of growing preferentially towards specific receivers, neurons actually have no particular affinity for any other neuron, but instead remain in a state of perpetual readiness to reconfigure circuits. They found that over the course of just a few hours, connections are formed and re-formed many times.

"The circuitry of the brain is like a social network where neurons are like people, directly linked to only a few other people," explains Markram. "This finding indicates that the brain is constantly switching alliances and linking with new circles of "friends" to better process information."

In their samples, the rewiring process was occurring continuously at a slow pace. By exciting the sample with glutamate, they found that the rate increased markedly. This suggests that with a strong new experience, the brain accelerates its reconfiguration process, allowing new connections to be made, tested, and strengthened, and weaker ones removed so that the brain is quickly better adapted to the new situation.

"This continual rewiring of the microcircuitry of the brain is like a Darwinian evolutionary process," notes Markram, "where a new experience triggers a burst of new connections between neurons, and only the fittest connections survive."

Markram emphasizes that these findings may have important implications for brain research, even at a practical level. "This discovery opens up a whole new frontier for researchers as we now try to understand the evolutionary process that sets the brain on a particular course. Perhaps it could even reveal ways to steer the brain around particular circuitry pathologies such as epilepsy."

Source: Ecole Polytechnique Fédérale de Lausanne

Explore further: Illuminating neural pathways in the living brain

Related Stories

Illuminating neural pathways in the living brain

July 24, 2017
Using light alone, scientists from the Max Planck Institute of Neurobiology in Martinsried are now able to reveal pairs or chains of functionally connected neurons under the microscope. The new optogenetic method, named Optobow, ...

Scientists capture first image of major brain receptor in action

July 24, 2017
Columbia University Medical Center (CUMC) researchers have captured the first three-dimensional snapshots of the AMPA-subtype glutamate receptor in action. The receptor, which regulates most electrical signaling in the brain, ...

Eye test could help diagnose autism

July 24, 2017
A new study out in European Journal of Neuroscience could herald a new tool that helps physicians identify a sub-group of people with Autism spectrum disorders (ASD). The test, which consists of measuring rapid eye movements, ...

Engineers invent the first bio-compatible, ion current battery

July 24, 2017
Engineers at the University of Maryland have invented an entirely new kind of battery. It is bio-compatible because it produces the same kind of ion-based electrical energy used by humans and other living things.

Scientists discover combined sensory map for heat, humidity in fly brain

July 20, 2017
Northwestern University neuroscientists now can visualize how fruit flies sense and process humidity and temperature together through a "sensory map" within their brains, according to new research.

Faulty support cells disrupt communication in brains of people with schizophrenia

July 20, 2017
New research has identified the culprit behind the wiring problems in the brains of people with schizophrenia. When researchers transplanted human brain cells generated from individuals diagnosed with childhood-onset schizophrenia ...

Recommended for you

Visual clues we use during walking and when we use them

July 25, 2017
(Medical Xpress)—A trio of researchers with the University of Texas and Rensselaer Polytechnic Institute has discovered which phase of visual information processing during human walking is used most to guide the feet accurately. ...

Male hepatitis B patients suffer worse liver ailments, regardless of lifestyle

July 25, 2017
Why men with hepatitis B remain more than twice as likely to develop severe liver disease than women remains a mystery, even after a study led by a recent Drexel University graduate took lifestyle choices and environments ...

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Study may explain failure of retinoic acid trials against breast cancer

July 25, 2017
Estrogen-positive breast cancers are often treated with anti-estrogen therapies. But about half of these cancers contain a subpopulation of cells marked by the protein cytokeratin 5 (CK5), which resists treatment—and breast ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Study shows a significant ongoing decline in sperm counts of Western men

July 25, 2017
In the first systematic review and meta-analysis of trends in sperm count, researchers from the Hebrew University-Hadassah Braun School of Public Health and Community Medicine and the Icahn School of Medicine at Mount Sinai ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.