• Germany's news in English

Scientists find fish 'compass' cells

The Local · 10 Jul 2012, 07:00

Published: 10 Jul 2012 07:00 GMT+02:00

Facebook Twitter Google+ reddit

Not only fish, but also birds, turtles, deer and cows orientate themselves according to the earth’s magnetic field. For decades, scientists have been at a loss to explain exactly where and how the “compass” works in these creatures.

But now a group of Munich scientists have located the relevant sensory cell in rainbow trout - close relatives of Pacific salmon, which return every year to their home rivers across 2,000 miles of open ocean.

Professor Michael Winklhofer, together with his team at Ludwig Maximilians University in Munich, found the cells in the part of the brain responsible for the fishes’ sense of smell. The team published their findings in the Proceedings PNAS science journal of the National Academy of Sciences.

The cells contain iron oxide magnetite, which is magnetic. This magnetic substance is made by the fish themselves, though the exact process remains unknown.

The magnetism of the cells means they can pick up information from the earth's magnetic field and convert this into a nervous impulse, helping to point the animal in the right direction.

Only one out of every 10,000 cells is magnetic, say the scientists. “That’s why there haven’t been any major breakthroughs in the search for a long time: because there are very few cells,” said Winklhofer. “The search for magnetic sensory cells is like the proverbial search for a needle in a haystack.”

It has long been known that animals could navigate using the earth’s magnetic field. In 1963, German zoologist Wolfgang Wiltschko discovered that migratory birds orientated themselves this way.

But how the internal compass worked has remained a mystery for almost half a century, though scientists discovered that a range of animals could do this – crabs, fish, deer and - of course - carrier pigeons.

Several years ago, scientists in Frankfurt and Munich detected very tiny particles of iron dioxide in the skin of the pigeons’ beaks, which turned out to be the magnetic receptors they had been searching for.

This April, a rival group of scientists at the University of Vienna published research in Nature journal suggesting the particles they had found were not parts of the “compass” nerve cells but part of the pigeons’ immune response against mucus.

Now the Munich scientists have managed to isolate whole cells containing high levels of iron oxide magnetite from the tissue of rainbow trout and prove they are magnetic. Using a magnetic field, the scientists were able to demonstrate that the cells rotated while the non-magnetic cells remained still.

Finding the cells is the first step in identifying the cell biology of the “compass” cell and the gene which allows some animals to produce the magnetic chemical.

“This is a very important step,” said Winklhofer. Once the gene structure of the cell is known, it can be compared with the human genome to establish whether humans now - or at any time in our evolution - also had “compass” cells.

“We don’t have any magnetic sense, or at least none is known to us,” said Winklhofer. “But it could of course be the case that our forefathers did have it. Maybe we also have cells that produce magnetite.”

Story continues below…

Large overhead electric pylons and undersea cables have been known to disrupt the magnetic field reception for many animals relying on their magnetic “compass” sense to get around.

Scientists believe it’s probable that humans have some inkling of this orientation sense – and that they can also feel it.

“The knowledge could be important in connection with electro smog,” said Winklhofer. More magnet cells in the body would raise the sensibility of certain individuals, explaining why some people suffer in the presence of electric power.

DAPD/The Local/jlb

The Local (news@thelocal.de)

Facebook Twitter Google+ reddit

Your comments about this article

10:39 July 10, 2012 by zeddriver
Oh great! Now that folks are debunking to a certain degree the climate change fiasco. Now they come up with magnetic smog. Sorry the local. You need to shut down or more than likely pay more to the government for a special green sticker certificate due to all the magnetic smog from the internet.
12:20 July 10, 2012 by wood artist
@zeddriver While I've not heard the term electro smog before, it is well establshed in medicine that some people are affected by thing such as power transmission lines. It's not usually a big thing, and simply driving by some doesn't trigger a response. However, doctors have studied people who live under or very close to lines in the US and the effect, while only afflicting a limited number of people, is very real. I don't recall a specific name for it...although I'm certain there is one...but this is not new, and has been scientifically proven.

It seems possible, though evidently not proven, that this "magnetic sensitivity" that birds and fish have might be related, so while it might seem "extreme" it's a very real situation for those who suffer. This just goes to show that research can lead in unknown directions, and sometimes you find things you weren't expecting...nor even looking for.

16:48 July 10, 2012 by zeddriver
@wood artist

It was not my intention to dismiss the effects out of hand. But. When scientists state things in the way this one did. "It disrupts the magnetic compass of animals" It just provides the anti human ecomentalists more fuel to further their efforts to get rid of humans. And gives the lazy politician an easy target to sell magnetic smog permits and of course to further their efforts to gain more control over the average citizen. Like all things scientific. It warrants further study. But in this instant information age. Some things are announced long before they are studied enough to make a sound decision on how to proceed. But the lack of sound information or positive proof has never gotten in the way of the politicians or activists over reactions to any given situation.
Today's headlines
Isis suspect charged with scouting Berlin attack sites
Photo: DPA

German federal prosecutors said Thursday they had brought charges against a 19-year-old Syrian man accused of having scouted targets in Berlin for a potential attack by the Isis terror group.

Berlin Holocaust memorial could not be built now: creator
The Memorial to the Murdered Jews of Europe, in Berlin. Photo: DPA.

The architect of the Berlin Holocaust memorial has said that, if he tried to build the monument again today, it would not be possible due to rising xenophobia and anti-Semitism in Germany and the United States.

'Liberal' Germany stopping Europe's 'slide into barbarism'
Ian Kershaw. Photo: DPA

Europe is not slipping into the same dark tunnel of hate and nationalism that it did in the 1930s - mainly thanks to Germany - one of the continent's leading historians has said.

Eurowings strike to hit 40,000 passengers
Travelers impacted by the strike on Thursday wait at Cologne Bonn airport. Photo: DPA.

The day-long strike by a Eurowings cabin crew union is expected to impact some 40,000 passengers on Thursday as hundreds of flights have been cancelled.

Deutsche Bank reports surprise quarter billion profit
Photo: DPA

Troubled German lender Deutsche Bank reported Thursday a surprise €256-million profit in the third quarter, compared with a loss of more than six billion in the same period last year.

US 'warned Merkel' against Chinese takeover of tech firm
Aixtron HQ. Photo: DPA

The German government withdrew its approval for a Chinese firm to purchase Aixtron, which makes semiconductor equipment, after the US secret services raised security concerns, a German media report said Wednesday.

Long-vanished German car brand joins electric race
Photo: DPA

Cars bearing the stamp of once-defunct manufacturer Borgward will once again roll off an assembly line in north Germany from 2018, the firm said Wednesday.

Eurowings cabin crew union to strike all day Thursday
Photo: DPA.

UPDATE: A union representing cabin crews on Lufthansa's budget airline Eurowings has announced that strikes will last all day Thursday as ongoing contract negotiations continue to falter.

Hesse hopes to set example by building Iraqi orphanages
Refugee children in northern Iraq. Photo: DPA

The wealthy central German state of Hesse has set aside €1 million to build a school, family homes and an orphanage in northern Iraq, in an effort to help refugees there.

The Local List
10 German clichés that foreigners get very wrong
David Hasselhoff. Photo: DPA

Whether it be efficiency, humourlessness or a love of a certain Baywatch star, there are many cliches stuck in the heads of foreigners about Germany. But how true are they?

10 German clichés that foreigners get very wrong
Sponsored Article
Last chance to vote absentee in the US elections
10 ways German completely messes up your English
Germany's 10 most weird and wonderful landmarks
10 things you never knew about socialist East Germany
How Germans fell in love with America's favourite squash
How I ditched London for Berlin and became a published author
12 clever German idioms that'll make you sound like a pro
23 fascinating facts you never knew about Berlin
9 unmissable events to check out in Germany this October
10 things you never knew about German reunification
10 things you're sure to notice after an Oktoberfest visit
Germany's 10 most Instagram-able places
15 pics that prove Germany is absolutely enchanting in autumn
10 German films you have to watch before you die
6 things about Munich that’ll stay with you forever
10 pieces of German slang you'll never learn in class
Ouch! Naked swimmer hospitalized after angler hooks his penis
Six reasons why Berlin is now known as 'the failed city'
15 tell-tale signs you’ll never quite master German
7 American habits that make Germans very, very uncomfortable
Story of a fugitive cow who outwitted police for weeks before capture
jobs available
Toytown Germany
Germany's English-speaking crowd