Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Structure essential for brain remodeling identified

08.12.2006
During learning and memory formation, the brain builds or remodels tiny structures on the surface of its nerve cells to store the new information. Now, a team led by Duke University Medical Center researchers has discovered where the brain gets the raw materials for such construction -- and has even taken "home movies" of the process.

The discovery, made in rodents, may lead to advances in understanding Alzheimer’s disease, autism and age-related memory loss, and could point to potential treatments for these and other neurological conditions, said senior study investigator Michael Ehlers, M.D., Ph.D., an associate professor of neurobiology and a Howard Hughes Medical Institute investigator at Duke.

The researchers published the findings in the Dec. 7, 2006, issue of the journal Neuron.

The research was funded by the National Institutes of Health, the American Health Assistance Foundation and the Raymond and Beverley Sackler Foundation.

The team focused on specific structures in brain nerve cells, or neurons, called dendritic spines. These are tiny bumps that form on the surface of dendrites, which extend off neurons like tree branches and receive chemical signals from other neurons. Each dendritic spine "talks" with its counterpart on a nearby neuron, and collectively the two structures comprise the "synapse" that links the neurons.

The brain stores new information by changing the structure of the synapses, Ehlers said. “If we need to remember a name, directions to a location or how to perform certain motor tasks -- anything involving learning or memory, really -- our brain does it by changing the properties of synapses,” he said.

During learning, synapses change in ways that make it easier for connected neurons to communicate with each other. This “plasticity” can occur in two ways. One way is structural, in which a synapse changes in size or shape; the other way is functional, in which connections between the synapses are strengthened by increasing the chemical signals sent or received by connected neurons.

In previous studies, Ehlers and colleagues at Duke found that certain cellular structures called recycling endosomes, which recycle used proteins within the cell, play an important role in controlling the functional type of plasticity. In the current study, the researchers sought to determine if recycling endosomes are involved in the structural type of plasticity as well.

To create a study model, the researchers transplanted neurons from rats into cell culture dishes. They then stimulated the neurons with chemicals and examined the cultures using a technique called live-cell imaging, in which a camera attached to a powerful microscope recorded the dendritic spines as they grew. This technique, Ehlers said, enabled the team to glimpse inside the internal world of the neuron to see how the recycling endosomes responded when neurons were stimulated.

When the scientists triggered the neurons, they saw the recycling endosomes, labeled with a green dye, streaming up and down the neurons, dipping in and out of the dendritic spines. Inside the dendritic spines, the recycling endosomes deposited pieces of recycled proteins that grew new spines or changed the shape and size of existing spines, Ehlers said.

The finding supported the team's theory that recycling endosomes transport the cargo that dendritic spines need to grow, Ehlers said.

Ehlers added that by providing a better understanding of how cells develop new synapses or strengthen existing synapses, the study may give researchers new ideas for developing drugs that target these critical cellular processes. A variety of neurological disorders, including Alzheimer’s disease, autism and early forms of age-related memory loss, are characterized by the loss of synapses or by the abnormal structural development of dendritic spines, he said.

A video will be available starting December 6, 2006 at 12 noon. To view, visit http://dukehealth.org/news/brain_remodeling.

Marla Vacek Broadfoot | EurekAlert!
Further information:
http://www.duke.edu

Further reports about: Synapse dendritic dendritic spines endosomes spine

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>