Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

29.04.2011
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.

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

William Harms | EurekAlert!
Further information:
http://www.uchicago.edu

Further reports about: circadian clock circadian rhythm internal clock

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>