Navigation Links
From the beginning, the brain knows the difference between night and day
Date:4/28/2011

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.


'/>"/>

Contact: William Harms
w-harms@uchicago.edu
773-702-8356
University of Chicago
Source:Eurekalert

Related biology news :

1. Shielding body protects brain from shell shocking blast injuries
2. Brain cell migration during normal development may offer insight on how cancer cells spread
3. USC research shows critical role of placenta in brain development
4. Evolution of human super-brain tied to development of bipedalism, tool-making
5. Toward new medications for chronic brain diseases
6. FDA approves the NovoTTF-100A system for the treatment of patients with recurrent glioblastoma multiforme (GBM) brain tumors
7. Giant fire-bellied toads brain brims with powerful germ-fighters
8. Allen Institute for Brain Science announces first comprehensive gene map of the human brain
9. Alcohol helps the brain remember, says new study
10. Mapping the brain: New technique poised to untangle the complexity of the brain
11. Dopamine controls formation of new brain cells
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/30/2017)... NEW YORK , March 30, 2017 ... by type (physiological and behavioral), by technology (fingerprint, AFIS, ... recognition, voice recognition, and others), by end use industry ... travel and immigration, financial and banking, and others), and ... Europe , Asia Pacific ...
(Date:3/27/2017)... N.Y. , March 27, 2017  Catholic ... Information and Management Systems Society (HIMSS) Analytics for ... EMR Adoption Model sm . In addition, CHS ... of U.S. hospitals using an electronic medical record ... for its high level of EMR usage in ...
(Date:3/23/2017)... -- The report "Gesture Recognition and Touchless Sensing Market by Technology ... Forecast to 2022", published by MarketsandMarkets, the market is expected to be worth ... and 2022. Continue Reading ... ... ...
Breaking Biology News(10 mins):
(Date:7/17/2017)... ... 2017 , ... DuPont Pioneer today announced the launch of ... dedicated to connecting third-party innovators with DuPont Pioneer scientists is now available and ... and digital solutions. , “DuPont Pioneer is building on its long history of ...
(Date:7/14/2017)... ... July 13, 2017 , ... Dr. Joshua Mondlick has ... implants into his practice, Mondlick Perio, in the Phoenix area. Dr. Mondlick ... first and only FDA cleared laser treatment to re-grow bone and with significantly less ...
(Date:7/13/2017)... ... 2017 , ... In’Tech Medical SAS ( http://www.intech-medical.com ), the ... of a major transaction with Eurazeo PME. The reputable French private equity comes ... In’Tech Medical’s service offerings while leveraging the company’s manufacturing expertise and global footprint. ...
(Date:7/13/2017)... ... July 13, 2017 , ... Microscan , the number-one brand ... sciences, will demonstrate advancements of the MicroHAWK platform for barcode reading and machine vision, ... at the AACC Clinical Lab Expo, taking place on August 1–3 in San Diego, ...
Breaking Biology Technology: