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:5/16/2017)... 16, 2017   Bridge Patient Portal , ... MD EMR Systems , an electronic medical ... GE, have established a partnership to build an ... the GE Centricity™ products, including Centricity Practice Solution ... These new integrations will allow healthcare delivery ...
(Date:4/18/2017)...  Socionext Inc., a global expert in SoC-based imaging and computing ... M820, which features the company,s hybrid codec technology. A demonstration utilizing ... Inc., will be showcased during the upcoming Medtec Japan at Tokyo ... Las Vegas Convention Center April 24-27. ... Click here for an image ...
(Date:4/11/2017)... 11, 2017 Crossmatch®, a globally-recognized leader ... today announced that it has been awarded a ... Activity (IARPA) to develop next-generation Presentation Attack Detection ... "Innovation has been a driving force within Crossmatch ... allow us to innovate and develop new technologies ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... New York, NY (PRWEB) , ... October 12, ... ... York Academy of Sciences today announced the three Winners and six Finalists of ... Awards are given annually by the Blavatnik Family Foundation and administered by the ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... the first-ever genomics analysis platform specifically designed for life science researchers to ... of pioneering researcher Rosalind Franklin, who made a major contribution to the ...
(Date:10/11/2017)... ... 11, 2017 , ... Proscia Inc ., a data ... titled, “Pathology is going digital. Is your lab ready?” with Dr. Nicolas Cacciabeve, ... and how Proscia improves lab economics and realizes an increase in diagnostic confidence.* ...
(Date:10/11/2017)... ... October 11, 2017 , ... Singh Biotechnology today announced ... to SBT-100, its novel anti-STAT3 (Signal Transducer and Activator of Transcription 3) B ... to cross the cell membrane and bind intracellular STAT3 and inhibit its function. ...
Breaking Biology Technology: