Featured Research

from universities, journals, and other organizations

Human/Insect/Jellyfish Genes Team To Quiet "Hyper" Nerve Cells

Date:
February 22, 1999
Source:
Johns Hopkins Medical Institutions
Summary:
With the help of fruit flies and jellyfish, Johns Hopkins scientists have proved they can quiet firing nerve cells -- at least temporarily -- by inserting the genetic version of an off switch.

With the help of fruit flies and jellyfish, Johns Hopkins scientists have proved they can quiet firing nerve cells -- at least temporarily -- by inserting the genetic version of an off switch.

Related Articles


The feat has possibilities as a gene therapy for conditions marked by nerve excitability or excessive firing, including epilepsy, severe pain, spastic muscles or the heartbeat arrhythmias that are still leading killers in Western society, says molecular cardiologist Eduardo Marbán, M.D., Ph.D., the research team leader.

In a study reported in the March Journal of Neuroscience, the researchers took "silencing genes" cloned from electrically quiet human heart tissue and ferried them into cultures of rat spinal tissue using non-harmful viruses that readily infect nerve cells.

Once turned on inside the spinal nerve cells, the genes generated fine channels in the cells' outer membranes. Potassium ions then flowed through the channels into cells, changing their electrical state to the equivalent of dead batteries. Within one to three days, the spinal cells, which normally fire rhythmically to the beat of an internal pacemaker, became still, says Marbán.

Taking the work a step further, the team also fitted the silencing genes with a control switch. That "switch" was a set of genes that insects such as flies rely upon to start or stop their various molting stages. A common insect hormone called ecdysone activates these genes whenever the insect grows too big for its exoskeleton. "Insects don't want to molt all the time," says Marbán, "so they've evolved this extremely effective and efficient switch as a way of controlling gene action."

In the Hopkins study, the genetic switch originally was recruited from fruit flies and its use marks the first time, the researchers say, such a system has been used in the context of gene therapy. To activate it, the researchers applied muristerone, a lab version of the insect hormone, to the nerve cell culture. The muristerone turned on the insect switch, which in turn activated the silencing genes. "The effect is not permanent. If muristerone is withheld, the nerve cells go back to their normal electrical activity in less than two days," says David Johns, Ph.D., who ran the study.

Hopes for clinical use, though well down the road, are positive, Marbán adds. "You might put silencing genes into pain nerve fibers," says Marbán, "and wait a few weeks, then try successively higher doses of muristerone until you get relief. If there's a bad effect, you can stop activating the system. We'd never be so bold to think about doing gene therapy for problems like this if we couldn't fine-tune what we were doing and reverse it."

The Hopkins group also developed a novel way to tell if the genes in their system are working, with a fluorescent green pigment that oceanic jellyfish use to signal each other. The researchers added a gene for this pigment, called GFP (for green fluorescent protein) in the middle of the switch-silencer gene system. When the system is active, the silenced nerve cells turn a bright green. "It's a quick, colorful way to see how fast and how intensely we're turning on gene expression," says Marbán.

The research was funded by grants from the National Institutes of Health and by the Tanabe Seiyaku Company in Japan. A patent for the gene system has been applied for.

Also on the research team were Ruth Marx, Ph.D., Richard Mains, Ph.D., and Brian O'Rourke, Ph.D.

--JHMI--

Related Web Sites: Invitrogen Web Resource -- http://www.invitrogen.com

Dana BrainWeb -- http://www.dana.org/brainweb (see epilepsy)

Johns Hopkins Medical Institutions' news releases are available on a PRE-EMBARGOED basis on EurekAlert at http://www.eurekalert.org, Newswise at http://www.newswise.com and from the Office of Communications and Public Affairs' direct e-mail news release service. To enroll, call 410-955-4288 or send e-mail to [email protected]

On a POST-EMBARGOED basis find them at http://hopkins.med.jhu.edu, Quadnet at http://www.quad-net.com and ScienceDaily at http://www.sciencedaily.com.


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. "Human/Insect/Jellyfish Genes Team To Quiet "Hyper" Nerve Cells." ScienceDaily. ScienceDaily, 22 February 1999. <www.sciencedaily.com/releases/1999/02/990219123026.htm>.
Johns Hopkins Medical Institutions. (1999, February 22). Human/Insect/Jellyfish Genes Team To Quiet "Hyper" Nerve Cells. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/1999/02/990219123026.htm
Johns Hopkins Medical Institutions. "Human/Insect/Jellyfish Genes Team To Quiet "Hyper" Nerve Cells." ScienceDaily. www.sciencedaily.com/releases/1999/02/990219123026.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. 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:

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