Featured Research

from universities, journals, and other organizations

New Growth-stimulating Cue Identified For Nerve Cells

Date:
July 24, 2003
Source:
Johns Hopkins Medical Institutions
Summary:
For decades, scientists have hunted for signals that guide nerve cells' tentacle-like axons, hoping to understand how these cell tips reach out to distant targets. It's knowledge that might one day help researchers learn how to rebuild nerves lost to spinal cord injuries or diseases like Huntington's.

For decades, scientists have hunted for signals that guide nerve cells' tentacle-like axons, hoping to understand how these cell tips reach out to distant targets. It's knowledge that might one day help researchers learn how to rebuild nerves lost to spinal cord injuries or diseases like Huntington's.

Related Articles


Now, a Johns Hopkins team studying a family of proteins best known for repelling axons and inhibiting their growth reports finding one member that unexpectedly promotes axon growth instead. In their experiments, rat nerves in the lab grew more and longer axons on the side nearest a source of this protein, called semaphorin-7a. Moreover, in mice without semaphorin-7a, axons of some odor-sensing nerve cells never reached their targets, the scientists report in the July 24 issue of Nature.

"I've been studying semaphorins for about a decade and didn't expect to find any that stimulated axon growth, certainly not to the extent we saw in the lab and in mice," says Alex Kolodkin, Ph.D., professor of neuroscience in The Johns Hopkins University School of Medicine's Institute for Basic Biomedical Sciences. "Now we need to figure out how semaphorins balance their repulsive and attractive effects."

Part of the answer to this paradox, Kolodkin says, is that semaphorin-7a interacts with different proteins than its relatives. In experiments with rat nerve cells involved in sensing odors, first author and postdoctoral fellow Jeroen Pasterkamp, Ph.D., found that semaphorin-7a spurs axon growth by hooking onto proteins called integrins, which are found on nerves and many other cell types.

Among their many roles, integrins (pronounced IN-teh-grins) help control cells' interactions with their surroundings by capturing chemical signals and conveying the messages to cells' internal machinery. Even though this is the first report to link semaphorins and integrins, both protein families are rapidly being recognized as major contributors to neurological function and disease, says Kolodkin.

"Because integrins are important throughout the body, targeting them to stimulate axon growth or re-growth in a particular area of the brain or spinal cord presents many problems," notes Pasterkamp. "Our next steps are to find out exactly how semaphorin-7a's message is passed along inside the nerve, which will hopefully reveal a useful, specific target for promoting axon growth following nerve injury or degeneration."

As the researchers learn more of the specifics about how semaphorin-7a differs from its relatives, they also hope to redraw their picture of how semaphorins as a family affect nerve development throughout life, they say.

The research was funded by the Kirsch Foundation, the National Institute of Neurological Disease and Stroke (part of the National Institutes of Health), the Netherlands Organization for Scientific Research and the Human Frontier Science Program.

Authors on the paper are Pasterkamp and Kolodkin of Johns Hopkins, and Jacques Peschon and Melanie Spriggs of Amgen Corporation, Seattle, Wash.


Story Source:

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


Cite This Page:

Johns Hopkins Medical Institutions. "New Growth-stimulating Cue Identified For Nerve Cells." ScienceDaily. ScienceDaily, 24 July 2003. <www.sciencedaily.com/releases/2003/07/030724082019.htm>.
Johns Hopkins Medical Institutions. (2003, July 24). New Growth-stimulating Cue Identified For Nerve Cells. ScienceDaily. Retrieved March 26, 2015 from www.sciencedaily.com/releases/2003/07/030724082019.htm
Johns Hopkins Medical Institutions. "New Growth-stimulating Cue Identified For Nerve Cells." ScienceDaily. www.sciencedaily.com/releases/2003/07/030724082019.htm (accessed March 26, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, March 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Ready to Pass Medicare Doc Bill

House Ready to Pass Medicare Doc Bill

AP (Mar. 26, 2015) In rare bipartisan harmony, congressional leaders pushed a $214 billion bill permanently blocking physician Medicare cuts toward House passage Thursday, moving lawmakers closer to resolving a problem that has plagued them for years. (March 26) Video provided by AP
Powered by NewsLook.com
HIV Outbreak Prompts Public Health Emergency In Indiana

HIV Outbreak Prompts Public Health Emergency In Indiana

Newsy (Mar. 26, 2015) Indiana Gov. Mike Pence says he will bring additional state resources to help stop the epidemic. Video provided by Newsy
Powered by NewsLook.com
AAA: Distracted Driving a Serious Teen Problem

AAA: Distracted Driving a Serious Teen Problem

AP (Mar. 25, 2015) While distracted driving is not a new problem for teens, new research from the AAA Foundation for Traffic Safety says it&apos;s much more serious than previously thought. (March 25) Video provided by AP
Powered by NewsLook.com
Obama: Affordable Care Act 'saving Lives'

Obama: Affordable Care Act 'saving Lives'

AP (Mar. 25, 2015) Speaking at a White House event marking the fifth anniversary of the Affordable Care Act, President Barack Obama says the law is "saving lives that touch all of us." (March 25) Video provided by AP
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