Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Signal found to enhance survival of new brain cells

12.11.2013
Implications for treating neurodegenerative disease, mental illness

A specialized type of brain cell that tamps down stem cell activity ironically, perhaps, encourages the survival of the stem cells' progeny, Johns Hopkins researchers report. Understanding how these new brain cells "decide" whether to live or die and how to behave is of special interest because changes in their activity are linked to neurodegenerative diseases such as Alzheimer's, mental illness and aging.


This is an illustration of parvalbumin-expressing interneurons delivering lifesaving chemical messengers to newborn neurons via tentacle-like synapses.

Credit: Mingxi Max Song and Gerald Sun

"We've identified a critical mechanism for keeping newborn neurons, or new brain cells, alive," says Hongjun Song, Ph.D., professor of neurology and director of Johns Hopkins Medicine's Institute for Cell Engineering's Stem Cell Program. "Not only can this help us understand the underlying causes of some diseases, it may also be a step toward overcoming barriers to therapeutic cell transplantation."

Working with a group led by Guo-li Ming, M.D., Ph.D., a professor of neurology in the Institute for Cell Engineering, and other collaborators, Song's research team first reported last year that brain cells known as parvalbumin-expressing interneurons instruct nearby stem cells not to divide by releasing a chemical signal called GABA.

In their new study, as reported Nov. 10 online in Nature Neuroscience, Song and Ming wanted to find out how GABA from surrounding neurons affects the newborn neurons that stem cells produce. Many of these newborn neurons naturally die soon after their "birth," Song says; if they do survive, the new cells migrate to a permanent home in the brain and forge connections called synapses with other cells.

To learn whether GABA is a factor in the newborn neurons' survival and behavior, the research team tagged newborn neurons from mouse brains with a fluorescent protein, then watched their response to GABA. "We didn't expect these immature neurons to form synapses, so we were surprised to see that they had built synapses from surrounding interneurons and that GABA was getting to them that way," Song says. In the earlier study, the team had found that GABA was getting to the synapse-less stem cells by a less direct route, drifting across the spaces between cells.

To confirm the finding, the team engineered the interneurons to be either stimulated or suppressed by light. When stimulated, the cells would indeed activate nearby newborn neurons, the researchers found. They next tried the light-stimulation trick in live mice, and found that when the specialized interneurons were stimulated and gave off more GABA, the mice's newborn neurons survived in greater numbers than otherwise. This was in contrast to the response of the stem cells, which go dormant when they detect GABA.

"This appears to be a very efficient system for tuning the brain's response to its environment," says Song. "When you have a high level of brain activity, you need more newborn neurons, and when you don't have high activity, you don't need newborn neurons, but you need to prepare yourself by keeping the stem cells active. It's all regulated by the same signal."

Song notes that parvalbumin-expressing interneurons have been found by others to behave abnormally in neurodegenerative diseases such as Alzheimer's and mental illnesses such as schizophrenia. "Now we want to see what the role of these interneurons is in the newborn neurons' next steps: migrating to the right place and integrating into the existing circuitry," he says. "That may be the key to their role in disease." The team is also interested in investigating whether the GABA mechanism can be used to help keep transplanted cells alive without affecting other brain processes as a side effect.

Link to the article: http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.3572.html

Other authors on the study were Juan Song, Jiaqi Sun, Zhexing Wen, Gerald J. Sun, Derek Hsu, Chun Zhong, Heydar Davoudi and Kimberly M. Christian of Johns Hopkins, and Jonathan Moss and Nicolas Toni of the University of Lausanne in Switzerland.

The study was funded by the National Institute of Neurological Disorders and Stroke (grant numbers NS047344 and NS048271), the National Institute of Environmental Health Sciences (grant number ES021957), the National Institute of Child Health and Human Development (grant number HD069184), the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation, the Brain and Behavior Research Foundation, the Maryland Stem Cell Research Fund, the Swiss National Science Foundation (grant number PP00A-119026/1) and the Fondation Leenaards.

Related stories:

Brain's Stem Cells 'Eavesdrop' to Find Out When to Act http://www.hopkinsmedicine.org/news/media/releases/brains_stem_cells

_eavesdrop_to_find_out_when_to_act

On Using Stem Cells in the Brain to Study Mental Disorders http://www.hopkinsmedicine.org/institute_cell_engineering/_includes/

videos/Transcriptions/Song_txn.html

Hopkins Researchers Uncover Key to Antidepressant Response http://www.hopkinsmedicine.org/news/media/releases/hopkins_researchers

_uncover_key_to_antidepressant_response

Shawna Williams | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht Hunting pathogens at full force
22.03.2017 | Helmholtz-Zentrum für Infektionsforschung

nachricht A 155 carat diamond with 92 mm diameter
22.03.2017 | Universität Augsburg

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

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars

22.03.2017 | Physics and Astronomy

New gel-like coating beefs up the performance of lithium-sulfur batteries

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>