Featured Research

from universities, journals, and other organizations

Overworked Brains Release Adenosine To Slow Cells, Trigger Sleep, UT Southwestern Researchers Find

Date:
April 23, 2005
Source:
University Of Texas Southwestern Medical Center At Dallas
Summary:
Why people get drowsy and fall asleep, and how caffeine blocks that process, are the subjects of a new study by researchers at UT Southwestern Medical Center.

DALLAS - April 20, 2005 - Why people get drowsy and fall asleep, and how caffeine blocks that process, are the subjects of a new study by researchers at UT Southwestern Medical Center.

Related Articles


When cells in a certain part of the brain become overworked, a compound in the brain kicks in, telling them to shut down. This causes people to become drowsy and fall asleep. Alter that natural process by adding coffee or tea, and the brain compound - called adenosine - is blocked, and people stay awake.

These findings, available online and in the April 21 issue of the journal Neuron, offer new clues regarding the function of the brain in the body's natural sleep process, as well as potential targets for future treatments for insomnia and other sleep problems.


Prolonged increased neural activity in the brain's arousal centers triggers the release of adenosine, which in turn slows down neural activity in the arousal center areas. Because the arousal centers control activity throughout the entire brain, the process expands outward and causes neural activity to slow down everywhere in the brain.

"Insomnia and chronic sleep loss are very common problems," said Dr. Robert W. Greene, professor of psychiatry and senior author of the study. "In addition, all the major psychiatric disorders, including depression, schizophrenia and post-traumatic stress disorder have sleep disruption as a prominent symptom.

"If we can understand better some of the factors involved in what makes us normally fall asleep, we can start to understand what might be going wrong when we don't."

Showing that increased brain cell activity triggers drowsiness also explains how caffeine works in helping people fight sleep.

"We knew that coffee kept us awake," Dr. Greene said. "Now we know why: Coffee and tea are blocking the link between the prolonged neural activity of waking and increased levels of adenosine in cells, which is why they prevent us from getting drowsy."

Past studies by Dr. Greene and his colleagues have shown that adenosine may act as a "fatigue factor." When adenosine levels increase in the arousal centers -- as happens with prolonged waking --  mammals tend to fall asleep. But what hasn't been known before is what triggers the release of adenosine to induce sleep.

"Neurons in the brain do things -- such as talk to each other, process information and coordinate body activities - which are called neural activity," said Dr. Greene.  "When they do this over a long period of time, more and more adenosine is released and feeds back onto the cells to quiet them down. It's like telling them: 'You guys have worked too hard; take it easy, and refresh yourselves.' "

"What we have shown in our study is that it's this prolonged neural activity of being awake that causes adenosine levels to go up, which in turn makes a person feel drowsy. It's the brain's way of achieving a proper balance between the neural activity of waking and the need for sleep. If something goes wrong with this adenosine system, you may end up with insomnia."

Other UT Southwestern researchers on the study were Dr. David Chapman, a postdoctoral researcher in psychiatry, and Dr. Dario Brambilla, a former postdoctoral researcher in psychiatry, now at the University of Milan Medical School in Italy.

The study was supported by the National Institute of Mental Health and the Department of Veterans Affairs.


Story Source:

The above story is based on materials provided by University Of Texas Southwestern Medical Center At Dallas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Texas Southwestern Medical Center At Dallas. "Overworked Brains Release Adenosine To Slow Cells, Trigger Sleep, UT Southwestern Researchers Find." ScienceDaily. ScienceDaily, 23 April 2005. <www.sciencedaily.com/releases/2005/04/050421213511.htm>.
University Of Texas Southwestern Medical Center At Dallas. (2005, April 23). Overworked Brains Release Adenosine To Slow Cells, Trigger Sleep, UT Southwestern Researchers Find. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2005/04/050421213511.htm
University Of Texas Southwestern Medical Center At Dallas. "Overworked Brains Release Adenosine To Slow Cells, Trigger Sleep, UT Southwestern Researchers Find." ScienceDaily. www.sciencedaily.com/releases/2005/04/050421213511.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) — Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com
Madagascar Working to Contain Plague Outbreak

Madagascar Working to Contain Plague Outbreak

AFP (Nov. 24, 2014) — Madagascar said Monday it is trying to contain an outbreak of plague -- similar to the Black Death that swept Medieval Europe -- that has killed 40 people and is spreading to the capital Antananarivo. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. 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