Featured Research

from universities, journals, and other organizations

Scientists Discover The Molecular Switch For Nerve Cells' Insulating Jelly Rolls

Date:
September 2, 2005
Source:
New York University Medical Center and School of Medicine
Summary:
Scientists identify the molecular switch that turns on the production of myelin, the fatty insulation around nerve cells that ensures swift and efficient communication in the nervous system. The finding may provide a new avenue for treating nervous system diseases such as multiple sclerosis, which are associated with damage to myelin.

Schwann cells produce the fatty insulin called myelin that surrounds some nerve fibers.
Credit: Image courtesy of New York University Medical Center and School of Medicine

Scientists at New York University School of Medicine report in a newstudy that they have identified the molecular switch that turns on theproduction of myelin, the fatty insulation around nerve cells thatensures swift and efficient communication in the nervous system. Thestudy, published in the September 1, 2005, issue of the journal Neuron,may provide a new avenue for treating nervous system diseases such asmultiple sclerosis, which are associated with damage to myelin.

A team led by James L. Salzer, M.D., Ph.D., Professor of CellBiology and Neurology at NYU School of Medicine, identified thelong-sought factor that determines whether or not nerve cells will bewrapped in thick layers of myelin, producing the biological equivalentof a jelly roll.

Using a sophisticated system for growing nerve cells inlaboratory dishes, the team identified a gene called neuregulin as themyelin signal. This signal directs Schwann cells, the nervous system'scellular architects, to build elaborate sheaths of myelin around theaxons of nerve cells. Axons are the long cable-like arms of nerve cellsthat send messages to other cells. The construction of myelin sheathhas been called one of the most beautiful examples of cellspecialization in nature.

Myelin forms the so-called white matter in the nervous systemand constitutes 50 percent of the weight of the brain. It is also animportant component of the spinal cord, and of nerves in other parts ofthe body. It has been known for almost 170 years that there are twokinds of axons --one is wrapped in myelin and appears white and theother is not and appears gray. Myelinated axons transmit messages inthe nervous system up to 100 times faster than their unmyelinatedcousins and are critical for proper neurological function. However, itwasn't known what actually initiated myelin production.

The neuregulin gene encodes a growth protein made by neurons.Last year a group of German scientists discovered that it wasimplicated in determining the thickness of the myelin sheath aroundaxons; however, until now it wasn't clear whether the gene alsoswitched on production of the sheath.

In a series of experiments, Dr. Carla Taveggia, the firstauthor of the study and an NYU research scientist, together withcollaborators at NYU, Columbia University College of Physicians andSurgeons, and other institutions, showed that unmyelinated neurons donot possess an active neuregulin gene and that myelinated neurons do.In the first set of experiments, they transplanted unmyelinated axonsfrom the peripheral nervous system (outside of the brain and spinalcord) of embryonic mice into laboratory dishes. They then added Schwanncells to the dishes. They observed that the Schwann cells sat on theaxons and did not produce any myelin.

In the next set of experiments, they inserted the neuregulingene into the unmyelinated axons. Instead of just sitting on the axons,the Schwann cells now produced thick myelin sheaths around them. So itappears that the gene instructs the Schwann cells to build the myelinwrap.

Dr. Salzer's group is investigating whether neuregulin has thesame effect on myelination in the central nervous system--the brain andspinal cord. If so, it may one day be possible to enhance or fixdamaged spinal cords and brain tracts that have lost their myelin dueto injury or disease by transplanting into, or turning on, afunctioning neuregulin gene in nerve cells. "Is it possible that thissame switch can reprogram a nerve cell that has lost myelin due toinjury or disease to repair itself? That is a key question that ourlaboratory and others are now actively trying to answer," he says.

###

Dr. Salzer's study was supported by grants from the NationalInstitutes of Health and the National Multiple Sclerosis Society, amongother groups.


Story Source:

The above story is based on materials provided by New York University Medical Center and School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

New York University Medical Center and School of Medicine. "Scientists Discover The Molecular Switch For Nerve Cells' Insulating Jelly Rolls." ScienceDaily. ScienceDaily, 2 September 2005. <www.sciencedaily.com/releases/2005/09/050902073203.htm>.
New York University Medical Center and School of Medicine. (2005, September 2). Scientists Discover The Molecular Switch For Nerve Cells' Insulating Jelly Rolls. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2005/09/050902073203.htm
New York University Medical Center and School of Medicine. "Scientists Discover The Molecular Switch For Nerve Cells' Insulating Jelly Rolls." ScienceDaily. www.sciencedaily.com/releases/2005/09/050902073203.htm (accessed August 29, 2014).

Share This




More Health & Medicine News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Who Could Be Burnt by WHO's E-Cigs Move?

Who Could Be Burnt by WHO's E-Cigs Move?

Reuters - Business Video Online (Aug. 28, 2014) The World Health Organisation has called for the regulation of electronic cigarettes as both tobacco and medical products. Ciara Lee looks at the impact of the move on the tobacco industry. Video provided by Reuters
Powered by NewsLook.com
CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

Newsy (Aug. 28, 2014) CDC director Tom Frieden says the Ebola outbreak is even worse than he feared. But he also said there's still hope to contain it. Video provided by Newsy
Powered by NewsLook.com
How A 'Rule Of Thumb' Could Slow Down Drinking

How A 'Rule Of Thumb' Could Slow Down Drinking

Newsy (Aug. 28, 2014) A study suggests people who follow a "rule of thumb" when pouring wine dispense less than those who don't have a particular amount in mind. Video provided by Newsy
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