Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Louder neurons form more connections

21.04.2005


As the brain develops, neurons reach out helter-skelter to form new connections, only a small number of which take hold. How the brain chooses which connections to keep and which to prune back appears to be governed by which branches have the most electrical activity-a finding that could help to explain how early experiences guide brain development.



The work, published in the April 21 issue of Nature, takes advantage of tiny, see-through zebrafish. Stephen Smith, PhD, professor of molecular and cellular physiology at the Stanford University School of Medicine, and his graduate student Jackie Hua immersed 3-day-old fish in a breathable, Jell-O-like substance that kept the fish alive but immobile. The researchers could then focus video cameras on the fish’s developing brain to watch how the branches of individual neurons grew and shrank over time.

It turns out that determining which of the branches will grow follows an age-old axiom: The squeaky neuron gets the grease. "Louder neurons drown out their quieter neighbors," Smith said.


Working out this seemingly simple rule took some technical finesse. Hua created zebrafish with a few brain cells that made a protein that prevented them from firing their normal electrical signals. These cells were also engineered to produce a protein that glowed green under the appropriate light.

Hua looked for green neurons in her immobilized fish to see how their branches fared compared with neighboring neurons that fired normally. The green neurons didn’t compete well.

Although the poorly-firing green neurons still formed extensive branching structures, which the researchers call the neuron’s arbor, most of those branches eventually receded while neighboring neurons formed a large number of stable connections. When the fish were five days old, the green neurons had a smaller, less complex arbor than those of neighboring neurons.

"We know that the arbor should occupy a certain amount of space, and in these fish it doesn’t take up that much space," Hua said.

Hua gave those losing neurons a fighting chance through another molecular twist. She managed to silence some neurons near the green, quietly-firing cells. When she did that, the green cells were able to compete successfully and formed longer, more complex arbors.

Although this work specifically examined the brains of fish, Smith said the same rules likely apply to all neurons, including those in the human brain. "Probably these same things are happening all the time," he said.

Neurons that fire regularly while learning to recognize a new person’s face, for example, will form larger arbors with more connections that help retain that memory for the future. Likewise, neurons stimulated by engaging toys or experiences will probably create larger arbors than similar neurons in less exciting conditions.

"We are looking at a dynamic part of development," Smith said. "These are the connections that let us think and fight and love."

Amy Adams | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Life Sciences:

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

nachricht Big data approach to predict protein structure
27.03.2017 | Karlsruher Institut für Technologie (KIT)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Big data approach to predict protein structure

27.03.2017 | Life Sciences

Parallel computation provides deeper insight into brain function

27.03.2017 | Life Sciences

Weather extremes: Humans likely influence giant airstreams

27.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>