Featured Research

from universities, journals, and other organizations

Researchers Identify Molecule Crucial To Adjusting Body's Internal Clock

Date:
December 6, 1999
Source:
University Of Illinois At Urbana-Champaign
Summary:
Is your biological clock out of kilter? Researchers say they have identified an important molecule in the retina-brain pathway that is crucial to adjusting the clock.

CHAMPAIGN, Ill. - Is your biological clock out of kilter? Researchers say they have identified an important molecule in the retina-brain pathway that is crucial to adjusting the clock.

Related Articles


In the Nov. 9 issue of the Proceedings of the National Academy of Sciences, the scientists point a finger at pituitary adenylyl cyclase-activating peptide (PACAP), whose function had been a mystery. In both animal and cellular studies, they found that PACAP works in concert with glutamate, another molecule in the nerve fibers between the retina and hypothalamus, home of the circadian clock.

"This study provides insight as to how the complex external signals that we encounter daily, such as the range of light intensities, are encoded and communicated to the brain," said Martha Gillette, the head of the department of cell and structural biology at the University of Illinois. "Light that you experience at night triggers the release of both glutamate and PACAP. The ratio probably depends on the intensity of the light stimulus."

Gillette's lab in 1994 reported that glutamate adjusts the clock in the presence of light at night. "PACAP fine tunes the glutamate signal," she said. "Together they convey more than just light is present. They encode information about light properties that is taken back to the clock, allowing it to adjust forward or backward appropriately."

The study - funded by the National Institute of Neurological Disorders and Stroke and the Danish Medical Research Council - focused on PACAP after a Danish group discovered that the molecule was localizing in the neural pathway. The question became what was PACAP doing?

"Adding exogenous PACAP together with glutamate had a negative effect on the amplitude of the clock-resetting effect of glutamate, which itself has the same effect on clock-resetting as light under laboratory conditions," Gillette said. "The surprise was that when we used fragments of the PACAP peptide as a control, the result was not that of glutamate alone. Rather, the effect was shifted in the opposite direction to increasing PACAP."

Applying antibodies to block the effect of PACAP that might be released from the optic nerve fibers in brain-slice preparations had the same effect. "This meant that PACAP was indeed released from the optic nerve when the glutamate was. It is a normal, silent component of the signal," she said.

This is likely the basis for why bright light at night keeps a person awake more effectively than dim light, Gillette said. Bright light delays clock time more and, thereby, makes it harder to awaken early the next morning. More PACAP in the light signal means a greater delay, she added.

Eventually, Gillette said, it may be possible to create drugs to selectively reset a person's sleep cycle, which would be welcome news for night-shift workers and for some people with sleep disorders.

The co-authors of the paper were Gillette, Dong Chen, Gordon F. Buchanan and Jian M. Ding, all of the U. of I., and Jens Hannibal, a professor of clinical biochemistry at the University of Copenhagen.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Researchers Identify Molecule Crucial To Adjusting Body's Internal Clock." ScienceDaily. ScienceDaily, 6 December 1999. <www.sciencedaily.com/releases/1999/12/991206071456.htm>.
University Of Illinois At Urbana-Champaign. (1999, December 6). Researchers Identify Molecule Crucial To Adjusting Body's Internal Clock. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/1999/12/991206071456.htm
University Of Illinois At Urbana-Champaign. "Researchers Identify Molecule Crucial To Adjusting Body's Internal Clock." ScienceDaily. www.sciencedaily.com/releases/1999/12/991206071456.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Technology Is Ruining Snow Days For Students

How Technology Is Ruining Snow Days For Students

Newsy (Jan. 25, 2015) More schools are using online classes to keep from losing time to snow days, but it only works if students have Internet access at home. Video provided by Newsy
Powered by NewsLook.com
Weird Things Couples Do When They Lose Their Phone

Weird Things Couples Do When They Lose Their Phone

BuzzFeed (Jan. 24, 2015) Did you back it up? Do you even know how to do that? Video provided by BuzzFeed
Powered by NewsLook.com
Smart Wristband to Shock Away Bad Habits

Smart Wristband to Shock Away Bad Habits

Reuters - Innovations Video Online (Jan. 23, 2015) A Boston start-up is developing a wristband they say will help users break bad habits by jolting them with an electric shock. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Amazing Technology Allows Blind Mother to See Her Newborn Son

Amazing Technology Allows Blind Mother to See Her Newborn Son

RightThisMinute (Jan. 23, 2015) Not only is Kathy seeing her newborn son for the first time, but this is actually the first time she has ever seen a baby. Kathy and her sister, Yvonne, have been legally blind since childhood, but thanks to an amazing new technology, eSight glasses, which gives those who are legally blind the ability to see, she got the chance to see the birth of her son. It&apos;s an incredible moment and an even better story. Video provided by RightThisMinute
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