Featured Research

from universities, journals, and other organizations

Dynamic behavior of progenitor cells in brain discovered

Date:
May 9, 2013
Source:
Johns Hopkins Medicine
Summary:
By monitoring the behavior of a class of cells in the brains of living mice, neuroscientists have discovered that these cells remain highly dynamic in the adult brain, where they transform into cells that insulate nerve fibers and help form scars that aid in tissue repair.

Montage of three images collected at one-week intervals showing an oligodendrocyte precursor cell migrating towards a lesion (white).
Credit: Ethan Hughes and Dwight Bergles

By monitoring the behavior of a class of cells in the brains of living mice, neuroscientists at Johns Hopkins discovered that these cells remain highly dynamic in the adult brain, where they transform into cells that insulate nerve fibers and help form scars that aid in tissue repair.

Published online April 28 in the journal Nature Neuroscience, their work sheds light on how these multipurpose cells communicate with each other to maintain a highly regular, grid-like distribution throughout the brain and spinal cord. The disappearance of one of these so-called progenitor cells causes a neighbor to quickly divide to form a replacement, ensuring that cell loss and cell addition are kept in balance.

"There is a widely held misconception that the adult nervous system is static or fixed, and has a limited capacity for repair and regeneration," says Dwight Bergles, Ph.D., professor of neuroscience and otolaryngology at the Johns Hopkins University School of Medicine. "But we found that these progenitor cells, called oligodendrocyte precursor cells (OPCs), are remarkably dynamic. Unlike most other adult brain cells, they are able to respond to the repair needs around them while maintaining their numbers."

OPCs can mature to become oligodendrocytes -- support cells in the brain and spinal cord responsible for wrapping nerve fibers to create insulation known as myelin. Without myelin, the electrical signals sent by neurons travel poorly and some cells die due to the lack of metabolic support from oligodendrocytes. It is the death of oligodendrocytes and the subsequent loss of myelin that leads to neurological disability in diseases such as multiple sclerosis.

During brain development, OPCs spread throughout the central nervous system and make large numbers of oligodendrocytes. Scientists know that few new oligodendrocytes are born in the healthy adult brain, yet the brain is flush with OPCs. However, the function of OPCs in the adult brain wasn't clear.

To find out, Bergles and his team genetically modified mice so that their OPCs contained a fluorescent protein along their edges, giving crisp definition to their many fine branches that extend in every direction. Using special microscopes that allow imaging deep inside the brain, the team watched the activity of individual cells in living mice for over a month.

The researchers discovered that, far from being static, the OPCs were continuously moving through the brain tissue, extending their "tentacles" and repositioning themselves. Even though these progenitors are dynamic, each cell maintains its own area by repelling other OPCs when they come in contact.

"The cells seem to sense each other's presence and know how to control the number of cells in their population," says Bergles. "It looks like this process goes wrong in multiple sclerosis lesions, where there are reduced numbers of OPCs, a loss that may impair the cells' ability to sense whether demyelination has occurred. We don't yet know what molecules are involved in this process, but it's something we're actively working on."

To see if OPCs do more than form new oligodendrocytes in the adult brain, the team tested their response to injury by using a laser to create a small wound in the brain. Surprisingly, OPCs migrated to the injury site and contributed to scar formation, a previously unsuspected role. The empty space in the OPC grid, created by the loss of the scar-forming OPCs, was then filled by cell division of neighboring OPCs, providing an explanation for why brain injury is often accompanied by proliferation of these cells.

"Scar cells are not oligodendrocytes, so the term 'oligodendrocyte precursor cell' may now be outdated," says Bergles. "These cells are likely to have a broader role in tissue regeneration and repair than we thought. Because traumatic brain injuries, multiple sclerosis and other neurodegenerative diseases require tissue regeneration, we are eager to learn more about the functions of these enigmatic cells."

Other authors of the report include Ethan Hughes, Shin Kang and Masahiro Fukaya of the Johns Hopkins University School of Medicine.

This work was supported by grants from the National Institute of Neurological Disorders and Stroke (F32NS076098, NS051509, NS050274) and the Brain Science Institute at The Johns Hopkins University.


Story Source:

The above story is based on materials provided by Johns Hopkins Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ethan G Hughes, Shin H Kang, Masahiro Fukaya, Dwight E Bergles. Oligodendrocyte progenitors balance growth with self-repulsion to achieve homeostasis in the adult brain. Nature Neuroscience, 2013; DOI: 10.1038/nn.3390

Cite This Page:

Johns Hopkins Medicine. "Dynamic behavior of progenitor cells in brain discovered." ScienceDaily. ScienceDaily, 9 May 2013. <www.sciencedaily.com/releases/2013/05/130509142142.htm>.
Johns Hopkins Medicine. (2013, May 9). Dynamic behavior of progenitor cells in brain discovered. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2013/05/130509142142.htm
Johns Hopkins Medicine. "Dynamic behavior of progenitor cells in brain discovered." ScienceDaily. www.sciencedaily.com/releases/2013/05/130509142142.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama 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:
from the past week

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