Social Media Sidebar


Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

Just because something doesn’t do what you planned it to do doesn’t mean it’s useless.


Thomas Edison

Magnetic fields light up GPS neurons, scientists say

Posted in Science on 27th Apr, 2012 07:21 PM by AlexMuller

The question of how birds navigate using - among other signals - magnetic fields is the subject of much debate.


These new "GPS neurons" seem to show how magnetic information is represented in birds' brains.


However, the study reported by Science leaves open the question of how they actually sense the magnetic field.


David Dickman of the Baylor College of Medicine in the US set up an experiment in which pigeons were held in place, while the magnetic field around them was varied in its strength and direction.


Prof Dickman and his colleague Le-Qing Wu believed that the 53 neurons were candidates for sensors, so they measured the electrical signals from each one as the field was changed.


Baylor College of Medicine
 Every neuron had its own characteristic response to the magnetic field, with each giving a sort of 3-D compass reading along the familiar north-south directions as well as pointing directly upward or downward.


In life, this could help the bird determine not only its heading just as a compass does, but would also reveal its approximate position.


Each cell also showed a sensitivity to field strength, with the maximum sensitivity corresponding to the strength of the Earth's natural field.


And just like a compass, the neurons had opposite responses to different field "polarity" - the magnetic north and south of a field, which surprised the researchers most of all.


"People had reported in the past, in a 1972 paper in Science, establishing that birds do not seem to respond to the polarity of the magnetic field, yet here we have neurons that are in fact doing that," Prof Dickman told BBC News.


"That's one of the beautiful aspects of what we've identified, because it shows how single brain cells can record multiple properties or complex qualities in a simple way."


'Be puzzled'
Several hypotheses hold that birds' magnetic navigation arises in cells that contain tiny chunks of metal in their noses or beaks, or possibly in an inner ear organ.


However, the most widely held among them was thrown into question recently when researchers found that purported compass cells in pigeon beaks were in fact a type of white blood cell.


Another theory suggests that a magnetic sense may come about in receptors in birds' eyes. When exposed to light, the theory says, molecules called cryptochromes undergo a fleeting change in their atomic makeup whose length depends on their alignment with a field.


 Pigeons have been shown to follow roads, but the real mystery is in their internal compass


The new work throws this latter possibility into question, as it would work equally well with a north- or south-pointing field.


Asked what an outsider should think, given that the recent results conflict with the two most plausible explanations for birds' remarkable navigation abilities, Prof Dickman said "be puzzled, because I am".


"We're leaning toward a third receptor in the inner ear, and we're doing experiments to try to determine whether it is in fact a receptor or not."


Henrik Mouritsen of the University of Oldenburg in Germany regards the current results with caution.


Read original article » Back to category


Author: Guest
Posted: 2013-11-22
より:After studying this positng, I pondered the exact same level that I invariably marvel about when scanning new blogs and forums. Just what do I take into consideration this? Exactly how ought to it impact me? This and additional posts in your weblog right right here actually give some stuff to look at. I basically ended up here via Yahoo after I was very first doing a little internet research for some course perform that I have. At all times very good occasions looking by the use of and I’m hopeful that you'll keep on writing new posts. Cheers! Reply


Recent headlines

  • Posted in Medicine on 2019-02-17 11:59:30
    Search to uncover genetic secrets of more
    Posted in Science on 2019-02-17 11:47:23
    Advancing personalized medicine research with open more
    Posted in Medicine on 2019-02-17 11:42:49
    New drug target to control onset of more
    Posted in Hardware on 2019-01-19 15:00:04
    SpaceX Orbital Starship Prototype Built By June 2019 more
    Posted in Hardware on 2019-01-19 14:18:47
    Apple and Samsung Hardest Hit as Smartphone more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs, more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target more

Recent Blog Posts

  • Posted by AlexMuller
    Even light drinking increases risk of more
    Posted by AlexMuller
    Researchers have discovered how to slow more
    Posted by AlexMuller
    Human retinas grown in a dish explain how color vision more
    Posted by AlexMuller
    The smartphone app that can tell you’re depressed before more
    Posted by AlexMuller
    Neural networks don’t understand what optical illusions more

Login to your Account

Login to your PlanetTech Account here

Remember me

Create a New Account

You just need username and password

The following errors occured:
Verify password:
Remember me