Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Light Receptors in Eye Play Key Role in Setting Biological Clock

19.08.2008
Biologists at the University of Virginia have discovered a switching mechanism in the eye that plays a key role in regulating the sleep/wake cycles in mammals.

The new finding demonstrates that light receptor cells in the eye are central to setting the rhythms of the brain's primary timekeeper, the suprachiasmatic nuclei, which regulates activity and rest cycles.

"The finding is significant because it changes our understanding of how light input from the eye can affect activity and sleep patterns," said Susan Doyle, a research scientist at U.Va. and the study's lead investigator.

The finding appears in the current issue of the Proceedings of the National Academy of Sciences.

The U.Va. researchers discovered that they could reverse the "temporal niche" of mice – meaning that the animals' activity phase could be switched from their normal nocturnality, or night activity, to being diurnal, or day active.

The investigators did this by both reducing the intensity of light given to normal mice, and also creating a new line of mutated mice with reduced light sensitivity in their eyes, which rendered them fully active in the day but inactive at night, a complete reversal of the normal activity/rest cycles of mice.

"This suggests that we have discovered an additional mechanism for regulating nocturnity and diurnity that is located in the light input pathways of the eye," Doyle said. "The significance of this research for humans is that it could ultimately lead to new treatments for sleep disorders, perhaps even eye drops that would target neural pathways to the brain's central timekeeper."

Biological clocks are the body's complex network of internal oscillators that regulate daily activity/rest cycles and other important aspects of physiology, including body temperature, heart rate and food intake. Besides sleep disorders, research in this field may eventually help treat the negative effects of shift work, aging and jet lag.

About 20 to 25 percent of U.S. workers are shift workers, many of whom have difficulty sleeping during the day when they are not working, and likewise find it hard to stay alert at night while on the job.

An estimated one in six people in the United States suffer from sleep disorders, including insomnia and excessive sleepiness. And as the U.S. population ages, a growing number of people are developing visual impairments that can result in sleep disorders.

"Currently, one in 28 Americans age 40 and over suffer from blindness or low vision, and this number is estimated to double in the next 15 years," Doyle said. "Our discovery of the switching mechanism in the eye has direct relevance with respect to the eventual development of therapies to treat circadian and sleep disorders in the visually impaired."

Doyle conducted her research with colleagues Tomoko Yoshikawa, a visiting scholar from Japan, and Holly Hillson, a U.Va. undergraduate student, in the laboratory of Michael Menaker, a leading researcher in the study of circadian rhythms. The work is funded by the National Institute for Mental Health.

Contact: Susan Doyle, lead researcher
434-982-5768 or sed5c@virginia.edu

Fariss Samarrai | Newswise Science News
Further information:
http://www.virginia.edu

More articles from Life Sciences:

nachricht Staying in Shape
16.08.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Chips, light and coding moves the front line in beating bacteria
16.08.2018 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>