Featured Research

from universities, journals, and other organizations

From the beginning, the brain knows the difference between night and day

Date:
April 28, 2011
Source:
University of Chicago
Summary:
The brain is apparently programmed from birth to develop the ability to determine sunrise and sunset, according to new research on circadian rhythms that research sheds new light on brain plasticity and may explain some basic human behaviors.

The brain is apparently programmed from birth to develop the ability to determine sunrise and sunset, new research on circadian rhythms at the University of Chicago shows.

The research sheds new light on brain plasticity and may explain some basic human behaviors, according to Brian Prendergast, associate professor in psychology at the University of Chicago and co-author of a paper published April 27 in the journal PLoS One. The lead author is August Kampf-Lassin, an advanced graduate student at the University.

"This finding may show us why infants of many species eventually learn to discriminate daytime from nighttime," said Prendergast, a researcher on biological rhythms.

In a series of experiments, researchers were able to show that although the ability to see visual stimuli, such as movement, is lost when a developing eye is not exposed to light, the ability to determine light and dark cycles was not affected. The ability to make that distinction between night and day develops as an animal grows, they found.

Other research has found that primates as well as humans adapt naturally to a rhythm of sleeping during the night. But this research shows that the pathway in the circadian system that allows synchrony between the brain and day-night rhythms in the environment is probably an innate feature of development, he said.

"For the first time, we have established that the ability to coordinate circadian rhythms with daily changes in light exposure is not subject to very much plasticity at all -- that it is not influenced by changes in the amount of light the brain receives during development," Kampf-Lassin said.

The results of the study are reported in the article "Experience-Independent Development of the Hamster Circadian Visual System," which was drawn from a series of challenging experiments with hamsters.

Shortly after the hamsters' eyes opened, but before they were exposed to light, experimenters placed a contact lens that completely blocked light over one of their eyes. Keeping one eye shut and one open, called monocular deprivation, is a standard method scientists use to study use-dependent plasticity of visual development.

The hamsters then grew up in a light-dark cycle such that only the non-deprived eye was able to send light information into the brain. In adulthood, the lenses were removed, and the function of the hamsters' previously deprived eye was assessed. The researchers found that the hamsters' brains were blind to all classical visual stimuli presented to the deprived eye, such as food or moving stimuli.

Nevertheless, the deprived eye perfectly retained the hamsters' ability to synchronize their circadian rhythms of activity with the 24-hour day. Thus, even though the hamsters could not see objects with the deprived eye, they could use input from the eye to set their internal clocks. The study also showed that long-term monocular deprivation did not affect anatomical projections from the eye to the circadian clock in the brain, and light-induced changes in gene expression in the circadian clock were also normal.

"It's interesting to see how some aspects of behavioral development are hard-wired and develop into adult-typical patterns, even in the total absence of normal environmental input to the system," Prendergast said.

Other authors on the paper were Jenny Wei and Jerome Galang, undergraduates at the University.


Story Source:

The above story is based on materials provided by University of Chicago. The original article was written by William Harms. Note: Materials may be edited for content and length.


Journal Reference:

  1. August Kampf-Lassin, Jenny Wei, Jerome Galang, Brian J. Prendergast. Experience-Independent Development of the Hamster Circadian Visual System. PLoS ONE, 2011; 6 (4): e16048 DOI: 10.1371/journal.pone.0016048

Cite This Page:

University of Chicago. "From the beginning, the brain knows the difference between night and day." ScienceDaily. ScienceDaily, 28 April 2011. <www.sciencedaily.com/releases/2011/04/110428151306.htm>.
University of Chicago. (2011, April 28). From the beginning, the brain knows the difference between night and day. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2011/04/110428151306.htm
University of Chicago. "From the beginning, the brain knows the difference between night and day." ScienceDaily. www.sciencedaily.com/releases/2011/04/110428151306.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. 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