Featured Research

from universities, journals, and other organizations

Light Receptor May Be Key In How Animals Use Earth's Magnetic Field

Date:
March 6, 2000
Source:
University Of Illinois At Urbana-Champaign
Summary:
A blue-light photoreceptor found in nerve layers of the eyes and brains has caught the attention of University of Illinois researchers who are seeking the magnetic compass that lets migratory birds and many other creatures find home using the magnetic field of Earth.

CHAMPAIGN, Ill. -- A blue-light photoreceptor found in nerve layers of the eyes and brains has caught the attention of University of Illinois researchers who are seeking the magnetic compass that lets migratory birds and many other creatures find home using the magnetic field of Earth.

The receptor -- cryptochrome -- is known to play a prominent role regulating an animal's day-and-night rhythm. Now, UI scientists report in the February issue of the Biophysical Journal that chemical experiments and computational modeling indicate that cryptochrome may be the site of a neurochemical reaction that lets birds, for example, process visual clues from the magnetic field and stay on course.

"Animals as diverse as migratory birds, salamanders, salmon, or hamsters use the geomagnetic field for orientation," said Klaus Schulten, holder of the UI Swanlund Chair in Physics and professor at the Beckman Institute for Advanced Science and Technology. "We know how such a compass works in bacteria, and we know that the magnetic compass ability is widespread in animals. But it has been a mystery how magnetoreception is achieved in higher animals."

Typical biomolecules interact with Earth's magnetic field too weakly to alter the course of their chemical reactions. In earlier experiments, Schulten had shown that certain chemical reactions involving so-called radical pairs can be influenced by weak magnetic fields, like that of a door magnet. Previous research had identified only cases in which bacteria as a whole, filled with magnetic particles, are being oriented like compass needles for swimming in the right direction.

Schulten's team, including doctoral student Thorsten Ritz, found theoretical evidence that a biochemical reaction involving cryptochromes can be influenced by an Earth-strength magnetic field. The computations were based on fundamental physics as described by the complex equations of quantum mechanics. The National Institutes of Health and the Roy J. Carver Charitable Trust funded the work.

Migratory birds and other animals, in many cases, cannot distinguish between north and south based on magnetic information alone. They can only detect the angle of the magnetic field lines with the horizon, which, Schulten said, is explained through symmetries in visual modulation patterns.

If radical-pair reactions in cryptochromes were connected by photoreception to the vision of animals, the magnetic field would modulate visual sensitivity, Schulten theorized. Animals would "see" the geomagnetic field by superimposing onto its visual images information about the field's direction.

Behavioral biologists tested Schulten's theory. They found that many magnetic responses require light, and that the orientation of some animals was erratic when exposed to monochromatic red light. Such findings strengthened the theory, Schulten and Ritz said, because radical-pair reactions require light above a certain energy threshold.

"The visual modulation patterns that we found show surprising agreement," Schulten said. "The hunt for the elusive magnetoreceptor is not over, but we have provided a new, promising track."


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Light Receptor May Be Key In How Animals Use Earth's Magnetic Field." ScienceDaily. ScienceDaily, 6 March 2000. <www.sciencedaily.com/releases/2000/03/000306080023.htm>.
University Of Illinois At Urbana-Champaign. (2000, March 6). Light Receptor May Be Key In How Animals Use Earth's Magnetic Field. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2000/03/000306080023.htm
University Of Illinois At Urbana-Champaign. "Light Receptor May Be Key In How Animals Use Earth's Magnetic Field." ScienceDaily. www.sciencedaily.com/releases/2000/03/000306080023.htm (accessed September 23, 2014).

Share This



More Earth & Climate News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: No Nation Gets Pass on Climate Change

Obama: No Nation Gets Pass on Climate Change

AP (Sep. 23, 2014) — In a forceful appeal for international cooperation on limiting carbon pollution, President Barack Obama warned world leaders at the UN Climate Summit on Tuesday that the globe's climate is changing faster than efforts to address it. (Sept. 23) Video provided by AP
Powered by NewsLook.com
Hundreds of Thousands Hit NYC Streets to Protest Climate Change

Hundreds of Thousands Hit NYC Streets to Protest Climate Change

AFP (Sep. 22, 2014) — Celebrities, political leaders and the masses rallied in New York and across the globe demanding urgent action on climate change, with organizers saying 600,000 people hit the streets. Duration: 01:19 Video provided by AFP
Powered by NewsLook.com
Raw: Protesters Stage Wall Street Climate Sit-in

Raw: Protesters Stage Wall Street Climate Sit-in

AP (Sep. 22, 2014) — A day after over 100,000 people marched against climate change, more than 1,000 activists blocked parts of Manhattan's financial district. Over 100 people, including a person wearing a white polar bear suit, were arrested Monday night. (Sept. 22) Video provided by AP
Powered by NewsLook.com
French FM Urges 'powerful' Response to Global Warming

French FM Urges 'powerful' Response to Global Warming

AFP (Sep. 22, 2014) — French Foreign Minister Laurent Fabius on Monday warned about the potential "catastrophe" if global warming was not dealt with in a "powerful" way. Duration: 01:08 Video provided by AFP
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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