Featured Research

from universities, journals, and other organizations

Overlooked cells hold keys to brain organization, disease, study shows

Date:
April 28, 2014
Source:
University of California - San Francisco
Summary:
Brain disease scientists may need to look beyond nerve cells and start paying attention to the star-shaped cells known as 'astrocytes,' because they play specialized roles in the development and maintenance of nerve circuits, and may contribute to a wide range of disorders, according to a new study. The researchers discovered in mice that a particular form of astrocyte within the spinal cord secretes a protein needed for survival of the nerve circuitry that controls reflexive movements. This discovery is the first demonstration that different types of astrocytes exist to support development and survival of distinct nerve circuits at specific locations within the central nervous system.

Scientists studying brain diseases may need to look beyond nerve cells and start paying attention to the star-shaped cells known as "astrocytes," because they play specialized roles in the development and maintenance of nerve circuits and may contribute to a wide range of disorders, according to a new study by UC San Francisco researchers.

In a study published online April 28, 2014 in Nature, the researchers report that malfunctioning astrocytes might contribute to neurodegenerative disorders such as Lou Gehrig's disease (ALS), and perhaps even to developmental disorders such as autism and schizophrenia.

David Rowitch, MD, PhD, UCSF professor of pediatrics and neurosurgery and a Howard Hughes Medical Institute investigator, led the research.

The researchers discovered in mice that a particular form of astrocyte within the spinal cord secretes a protein needed for survival of the nerve circuitry that controls reflexive movements. This discovery is the first demonstration that different types of astrocytes exist to support development and survival of distinct nerve circuits at specific locations within the central nervous system.

Astrocytes vastly outnumber signal-conducting neurons, and make up the majority of cells in the brain. But where neuroscientists are accustomed to seeing only vanilla when it comes to astrocytes -- viewing all of them as similar despite their different locations in brain and spinal cord -- they now will have to imagine "31 flavors" or more.

There might even be hundreds of distinctive varieties of astrocytes performing specific functions in different locations, according to Rowitch, chief of neonatology for UCSF Benioff Children's Hospital San Francisco.

"Our study shows roles for specialized astrocytes that function to support particular kinds of neurons in their neighborhood," Rowitch said.

Led by Rowitch lab postdoctoral fellow Anna Molofsky, MD, PhD, the researchers studied the spinal cord sensory motor circuit, which allows both mice and humans to react without thought -- to jerk a limb away from something hot, for instance.

The team discovered that a protein called Sema3a is produced much more abundantly by astrocytes close to motor neurons than by astrocytes from other regions in the spinal cord. They concluded that motor neurons required this source of Sema3a from the local astrocytes, because when Sema3a production was blocked, the motor neurons failed to form normal connections, and half of them died.

Motor neurons also die in ALS, a fatal neurodegenerative disease, and in spinal muscular atrophy, a disease that can affect newborn infants. In other studies, scientists have found that abnormal astrocytes can have toxic effects on motor neurons.

Molofsky is a psychiatrist who studies how astrocytes organize nerve circuits, and how disruptions of these nerve circuits during development or disease may involve abnormal astrocyte function. Disrupted neural circuits are believed to be responsible for certain psychiatric disorders.

"The immediate implications of this study are for diseases of motor neurons, like ALS, but I think our findings might also apply more generally to diseases of neural-circuit formation in the brain such as autism, schizophrenia and epilepsy," Molofsky said. "To achieve a comprehensive understanding of how neural circuits form and are maintained, it seems important that we integrate knowledge of how astrocytes support that process."

Rowitch agrees. "To the extent that psychiatric or neurological disease is localized to a specific part of the brain, we should now be considering the potentially specialized type of astrocytes regulating nerve connections in that region and their contributions to disease," he said.


Story Source:

The above story is based on materials provided by University of California - San Francisco. Note: Materials may be edited for content and length.


Journal Reference:

  1. Anna V. Molofsky, Kevin W. Kelley, Hui-Hsin Tsai, Stephanie A. Redmond, Sandra M. Chang, Lohith Madireddy, Jonah R. Chan, Sergio E. Baranzini, Erik M. Ullian, David H. Rowitch. Astrocyte-encoded positional cues maintain sensorimotor circuit integrity. Nature, 2014; DOI: 10.1038/nature13161

Cite This Page:

University of California - San Francisco. "Overlooked cells hold keys to brain organization, disease, study shows." ScienceDaily. ScienceDaily, 28 April 2014. <www.sciencedaily.com/releases/2014/04/140428121203.htm>.
University of California - San Francisco. (2014, April 28). Overlooked cells hold keys to brain organization, disease, study shows. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2014/04/140428121203.htm
University of California - San Francisco. "Overlooked cells hold keys to brain organization, disease, study shows." ScienceDaily. www.sciencedaily.com/releases/2014/04/140428121203.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins