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 Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>