Featured Research

from universities, journals, and other organizations

Fight-or-flight chemical prepares cells to shift the brain from subdued to alert state

Date:
June 18, 2014
Source:
Johns Hopkins Medicine
Summary:
Brain cells, called astrocytes because of their star-shaped appearance, can monitor and respond to nearby neural activity, but only after being activated by the fight-or-flight chemical norepinephrine. Because astrocytes can alter the activity of neurons, the findings suggest that astrocytes may help control the brain’s ability to focus.

Astrocyte activity is shown in green in this slice of tissue from the brain region that controls movement in mice. Internal, structural elements of the astrocytes are shown in magenta; cell bodies are in red.
Credit: Amit Agarwal and Dwight Bergles, courtesy of Cell Press

A new study from The Johns Hopkins University shows that the brain cells surrounding a mouse's neurons do much more than fill space. According to the researchers, the cells, called astrocytes because of their star-shaped appearance, can monitor and respond to nearby neural activity, but only after being activated by the fight-or-flight chemical norepinephrine. Because astrocytes can alter the activity of neurons, the findings suggest that astrocytes may help control the brain's ability to focus.

The study involved observing the cells in the brains of living, active mice over long periods of time. A combination of genetically engineered mice and advanced microscopy allowed the researchers to visualize the activity of astrocyte networks in different regions of the brain to learn how these abundant supporting cells are controlled.

The scientists monitored astrocytes in the area of the brain responsible for controlling movement and saw that the cells often increased their activity as the mice walked on treadmills -- but not always, and sometimes astrocytes became active when the animals were not moving. This lack of consistency suggested to the researchers that the astrocytes were not responding to nearby neurons, as had been thought.

Similarly, astrocytes in the vision processing area of the brain did not necessarily become active when the mice were stimulated with light, but they were sometimes active, even in the dark. The team solved both mysteries when they tested the idea that the astrocytes needed a signal to "wake them up" before they could respond to nearby neurons. That is how they found that norepinephrine, the brain's broadly distributed fight-or-flight signal, primes the astrocytes in both locations to "listen in" on nearby neuronal activity.

"Astrocytes are among the most abundant cells in the brain, but we know very little about how they are controlled and how they contribute to brain function," says Dwight Bergles, Ph.D., professor of neuroscience, who led the study. "Since memory formation and other important functions of the brain require a state of attention, we're interested in learning more about how astrocytes help create that state."

For example, Bergles says, "We know that astrocytes can regulate local blood flow, provide energy to neurons and release signaling molecules that alter neuronal activity. They could be doing any or all of those things in response to being activated. It is also possible that they act as a sort of megaphone to broadcast local norepinephrine signals to every neuron in the brain." Whatever the case may be, researchers now know that astrocytes are not idle loiterers. This ability to study astrocyte network activity in animals as they do different things will help to reveal how these cells contribute to brain function.

This research will be published in the journal Neuron on June 18.


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. Martin Paukert, Amit Agarwal, Jaepyeong Cha, VanA. Doze, JinU. Kang, DwightE. Bergles. Norepinephrine Controls Astroglial Responsiveness to Local Circuit Activity. Neuron, 2014; 82 (6): 1263 DOI: 10.1016/j.neuron.2014.04.038

Cite This Page:

Johns Hopkins Medicine. "Fight-or-flight chemical prepares cells to shift the brain from subdued to alert state." ScienceDaily. ScienceDaily, 18 June 2014. <www.sciencedaily.com/releases/2014/06/140618131915.htm>.
Johns Hopkins Medicine. (2014, June 18). Fight-or-flight chemical prepares cells to shift the brain from subdued to alert state. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/06/140618131915.htm
Johns Hopkins Medicine. "Fight-or-flight chemical prepares cells to shift the brain from subdued to alert state." ScienceDaily. www.sciencedaily.com/releases/2014/06/140618131915.htm (accessed September 1, 2014).

Share This




More Mind & Brain News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Coffee Then Napping: The (New) Key To Alertness

Coffee Then Napping: The (New) Key To Alertness

Newsy (Aug. 30, 2014) Researchers say having a cup of coffee then taking a nap is more effective than a nap or coffee alone. Video provided by Newsy
Powered by NewsLook.com
Young Entrepreneurs Get $100,000, If They Quit School

Young Entrepreneurs Get $100,000, If They Quit School

AFP (Aug. 29, 2014) Twenty college-age students are getting 100,000 dollars from a Silicon Valley leader and a chance to live in San Francisco in order to work on the start-up project of their dreams, but they have to quit school first. Duration: 02:20 Video provided by AFP
Powered by NewsLook.com
Baby Babbling Might Lead To Faster Language Development

Baby Babbling Might Lead To Faster Language Development

Newsy (Aug. 29, 2014) A new study suggests babies develop language skills more quickly if their parents imitate the babies' sounds and expressions and talk to them often. Video provided by Newsy
Powered by NewsLook.com
Electrical Stimulation Boosts Brain Function, Study Says

Electrical Stimulation Boosts Brain Function, Study Says

Newsy (Aug. 29, 2014) Researchers found an improvement in memory and learning function in subjects who received electric pulses to their brains. 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