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 July 28, 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 July 28, 2014).

Share This




More Earth & Climate News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
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:
from the past week

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