Featured Research

from universities, journals, and other organizations

Without Glial Cells, Animals Lose Their Senses

Date:
November 7, 2008
Source:
Rockefeller University
Summary:
Scientists show that while neurons play the lead role in detecting sensory information, a second type of cell, the glial cell, pulls the strings behind the scenes. The findings, point to a mechanism that may explain not only how glia are required for bringing sensory information into the brain but also how glia may influence connections between neurons deep within in it.

Frayed nerves. New research in a C. elegans sensory organ shows that the branch-like ends of neurons (red) shrivel into nubs in the absence of glia (green).
Credit: Image courtesy of Rockefeller University

Sensory neurons have always put on a good show. But now, it turns out, they'll be sharing the credit. Rockefeller University scientists now show that while neurons play the lead role in detecting sensory information, a second type of cell, the glial cell, pulls the strings behind the scenes.

The findings, point to a mechanism that may explain not only how glia are required for bringing sensory information into the brain but also how glia may influence connections between neurons deep within in it.

"This is a convincing demonstration that glia play an essential role in the function of the nervous system," says Shai Shaham, head of the Laboratory of Developmental Genetics. "Without sensory neurons, animals can't sense their environment and react to it. What we found is that glia are required for the activity of these neurons and that glia are required to establish the quality of the animal's response to its environment."

In their work, Shaham, graduate student Taulant Bacaj, and postdoctoral fellow Maya Tevlin worked with a structure called the amphid, a sensory organ in the C. elegans nervous system that contains glia and neurons. Of the organ's 12 neurons, four are completely ensheathed by glia and eight are partially ensheathed, with sensory endings exposed to the outside environment (via the worm's nose). To see what glia do for these neurons, Bacaj removed the glia and observed the effect on the neurons' shape, their ability to generate behavior when exposed to odors and temperatures, and their ability to absorb certain dyes.

The results were striking. The absence of glia affected at least one of these three properties in each of the neurons, suggesting that glia not only regulate all of these properties but that they specifically regulate them in different neurons. In the absence of glia, for example, the sensory endings of the ensheathed neurons lost their intricate branch-like structure, shriveling into nubs. However, the partially ensheathed neurons retained their normal shape, despite their inability to respond to stimuli in their environment..

"Instead of finding their perfect temperature, the worms kept crawling toward warmer and warmer regions," says Bacaj. "Also, they didn't avoid odors they didn't like and weren't drawn to odors that they did like, suggesting that the neurons could not coordinate an appropriate behavioral response."

"It's a new layer of complexity that was never described before," says Shaham.

To get a molecular handle on how glia regulate the functions of neurons, Shaham, Tevlin and Bacaj looked at which proteins are expressed more in glial cells than in any other cell in C. elegans. They found that one of these proteins, called FIG-1, was exclusively expressed in glia surrounding the amphid sensory organ (and its sister organ in the tail). When the glia secreted this protein, neurons in the sensory organ could sense the environment; without it, the neurons had difficulties in picking up specific sensory cues.

Because FIG-1 resembles a human protein called thrombospondin, which is secreted by glia in vertabrates, the results suggest that interactions between neurons and glia in C. elegans may be similar to those in humans. They also suggest that glia-neuron interactions at sensory organs may provide insight into glia-neuron interactions at synapses, connection sites between neurons deep within the brain.

"The FIG-1 protein is similar to a glial protein found at vertebrate synapses," says Shaham. "So we think there might be a connection between glial proteins in C. elegans and those in vertebrates. The difference is that at synapses, you have a neuron receiving information from another neuron, whereas at sensory organs, a neuron is receiving information from the outside world."


Story Source:

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


Journal Reference:

  1. Taulant Bacaj, Maya Tevlin, Yun Lu, Shai Shaham. Glia Are Essential for Sensory Organ Function in C. elegans. Science, October 31, 2008, Vol. 322. no. 5902, pp. 744 - 747 DOI: 10.1126/science.1163074

Cite This Page:

Rockefeller University. "Without Glial Cells, Animals Lose Their Senses." ScienceDaily. ScienceDaily, 7 November 2008. <www.sciencedaily.com/releases/2008/10/081030144624.htm>.
Rockefeller University. (2008, November 7). Without Glial Cells, Animals Lose Their Senses. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2008/10/081030144624.htm
Rockefeller University. "Without Glial Cells, Animals Lose Their Senses." ScienceDaily. www.sciencedaily.com/releases/2008/10/081030144624.htm (accessed August 27, 2014).

Share This




More Mind & Brain News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Newsy (Aug. 26, 2014) A study published in the journal "Neurology" interviewed more than 19,000 people and found 15 percent suffer from being "sleep drunk." Video provided by Newsy
Powered by NewsLook.com
Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Newsy (Aug. 26, 2014) A new study found fewer deaths from prescription drug overdoses in states that have legalized medical marijuana. But experts disagree on the results. Video provided by Newsy
Powered by NewsLook.com
Heart Group: E-Cigarettes May Help Smokers Quit

Heart Group: E-Cigarettes May Help Smokers Quit

AP (Aug. 25, 2014) The American Heart Association's first policy statement on electronic cigarettes backs them as a last resort to help smokers quit and calls for more regulation to keep them away from youth. (Aug. 25) Video provided by AP
Powered by NewsLook.com
Doctors Push For Later Start Times As School Year Kicks Off

Doctors Push For Later Start Times As School Year Kicks Off

Newsy (Aug. 25, 2014) The American Academy of Pediatrics is the latest group pushing for middle schools and high schools to start later, for the sake of their kids. 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