Featured Research

from universities, journals, and other organizations

Brain 'GPS' illuminated in migratory monarch butterflies

Date:
January 27, 2011
Source:
Cell Press
Summary:
A new study takes a close look at the brain of the migratory monarch butterfly to better understand how these remarkable insects use an internal compass and skylight cues to navigate from eastern North America to Mexico each fall. The research provides key insights into how ambiguous sensory signals can be integrated in the brain to guide complex navigation.

A monarch butterfly.
Credit: iStockphoto/Brandon Laufenberg

A new study takes a close look at the brain of the migratory monarch butterfly to better understand how these remarkable insects use an internal compass and skylight cues to navigate from eastern North America to Mexico each fall. The research, published by Cell Press in the January 27 issue of the journal Neuron, provides key insights into how ambiguous sensory signals can be integrated in the brain to guide complex navigation.

Previous research has shown that migrants use a time-compensated "sun compass" to maintain a southerly direction during flight. "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," explains senior study author, 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."

Dr. Reppert and coauthor Dr. Stanley Heinze were interested in studying exactly how skylight cues are processed by migrating monarchs and how the skylight pattern of polarized light may provide directional information on cloudy days. "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," says Dr. Reppert. "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. 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. He went on to show 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. Interestingly, the responses of individual neurons to these two different stimuli were mediated through different parts of the monarch eye. The responses were then integrated in the sun compass part of the monarch brain to form an accurate representation of skylight cues throughout the day.

"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," conclude 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."


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stanley Heinze, Steven M. Reppert. Sun Compass Integration of Skylight Cues in Migratory Monarch Butterflies. Neuron, 2011; 69 (2): 345-358 DOI: 10.1016/j.neuron.2010.12.025

Cite This Page:

Cell Press. "Brain 'GPS' illuminated in migratory monarch butterflies." ScienceDaily. ScienceDaily, 27 January 2011. <www.sciencedaily.com/releases/2011/01/110126121450.htm>.
Cell Press. (2011, January 27). Brain 'GPS' illuminated in migratory monarch butterflies. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2011/01/110126121450.htm
Cell Press. "Brain 'GPS' illuminated in migratory monarch butterflies." ScienceDaily. www.sciencedaily.com/releases/2011/01/110126121450.htm (accessed September 22, 2014).

Share This



More Earth & Climate News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
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
Ongoing Drought, Fighting Put Somalia at Risk of Famine

Ongoing Drought, Fighting Put Somalia at Risk of Famine

AFP (Sep. 22, 2014) After a year of poor rains and heavy fighting Somalia is again at risk of famine, just three years after food shortages killed 260,000 people. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Rockefeller Oil Heirs Switching To Clean Energy

Rockefeller Oil Heirs Switching To Clean Energy

Newsy (Sep. 22, 2014) The Rockefellers — heirs to an oil fortune that made the family name a symbol of American wealth — are switching from fossil fuels to clean energy. 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:

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