How migratory butterflies use ‘compass and sunlight’ to find their way
January 27th, 2011 - 5:54 pm ICT by ANI
Washington, Jan 27 (ANI): A new study examines how migratory monarch butterflies use an internal compass and skylight cues to navigate from eastern North America to Mexico each fall.
“In general, this sun compass mechanism proposes that skylight cues providing directional information are sensed by the eyes and that this sensory information is then transmitted to a sun compass system in the brain,” said Dr. Steven Reppert from the University of Massachusetts Medical School.
“There, information from both eyes is integrated and time compensated for the sun’s movement by a circadian clock so that flight direction is constantly adjusted to maintain a southerly bearing over the day.”
“The pattern of linearly polarized skylight is arranged as concentric circles of electric field vectors (E-vectors) around the sun, and they can indicate the sun’s position, even when the sun itself is covered with clouds,” he said.
“However, the symmetrical nature of the polarized skylight pattern leads to directional uncertainty unless the pattern is integrated with the horizontal position of the sun, called the solar azimuth.”
Dr. Stanley Heinze compared the neuronal organization of the monarch brain sun compass network to that of the well-characterized desert locust and found it to be remarkably similar.
Then he showed that individual neurons in the sun compass were tuned to specific E-vector angles of polarized light, as well as azimuth-dependent responses to unpolarized light.
“Our results reveal the general layout of the neuronal machinery for sun compass navigation in the monarch brain and provide insights into a possible mechanism of integrating polarized skylight information and solar azimuth,” concluded the authors.
“More generally, our results address a fundamental problem of sensory processing by showing how seemingly contradictory skylight signals are integrated into a consistent, neural representation of the environment.”
The study is published by Cell Press in the January 27 issue of the journal Neuron. (ANI)
- Insects watch skies to navigate - Jan 18, 2012
- How butterflies navigate using Earth's magnetic field - Jan 26, 2010
- How nerve cells unravel jumbled information - Nov 21, 2011
- Electrical oscillations key for storing info in brain - Apr 30, 2011
- IBM unveils computing chips that mimic human brain - Aug 18, 2011
- How marijuana affects the way the brain processes emotional info - Apr 06, 2011
- 'Light-smelling' mice may explain how we distinguish between scents - Oct 18, 2010
- Neuroscientists track how brain cells process information - Jul 13, 2011
- Protein turns harmless grasshoppers into destructive swarms - Dec 21, 2011
- Vikings used glowing 'sunstone' to navigate on cloudy days - Jan 31, 2011
- Why normal kids with Rett syndrome become abnormal later? - Apr 14, 2011
- Scientists decode brain activity of monkeys - Jul 22, 2012
- Some sharks navigate to specific locations up to 50km away: Study - Mar 02, 2011
- Some sharks follow 'mental map' to navigate seas - Mar 10, 2011
- Robotic arm to reveal inner working of brain cells - May 07, 2012
Tags: circadian clock, compass navigation, compass system, concentric circles, desert locust, directional uncertainty, dr stanley, dr steven, fundamental problem, horizontal position, internal compass, massachusetts medical school, monarch butterflies, neural representation, skylight, solar azimuth, sun compass, symmetrical nature, university of massachusetts, university of massachusetts medical school