Hunger affects decision making and perception of risk

Public release date: 25-Jun-2013
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Contact: Dr. Stefanie Merker
merker@neuro.mpg.de
49-898-578-3514
Max-Planck-Gesellschaft

Different neural circuits process environmental signals depending on the state of satiation

This news release is available in German.

Hungry people are often difficult to deal with. A good meal can affect more than our mood, it can also influence our willingness to take risks. This phenomenon is also apparent across a very diverse range of species in the animal kingdom. Experiments conducted on the fruit fly, Drosophila, by scientists at the Max Planck Institute of Neurobiology in Martinsried have shown that hunger not only modifies behaviour, but also changes pathways in the brain.

Animal behaviour is radically affected by the availability and amount of food. Studies prove that the willingness of many animals to take risks increases or declines depending on whether the animal is hungry or full. For example, a predator only hunts more dangerous prey when it is close to starvation. This behaviour has also been documented in humans in recent years: one study showed that hungry subjects took significantly more financial risks than their sated colleagues.

Also the fruit fly, Drosophila, changes its behaviour depending on its nutritional state. The animals usually perceive even low quantities of carbon dioxide to be a sign of danger and opt to take flight. However, rotting fruit and plants the flies' main sources of food also release carbon dioxide. Neurobiologists in Martinsried have now discovered how the brain deals with this constant conflict in deciding between a hazardous substance and a potential food source taking advantage of the fly as a great genetic model organism for circuit neuroscience.

In various experiments, the scientists presented the flies with environments containing carbon dioxide or a mix of carbon dioxide and the smell of food. It emerged that hungry flies overcame their aversion to carbon dioxide significantly faster than fed flies if there was a smell of food in the environment at the same time. Facing the prospect of food, hungry animals are therefore significantly more willing to take risks than sated flies. But how does the brain manage to decide between these options?

Avoiding carbon dioxide is an innate behaviour and should therefore be generated outside the mushroom body in the fly's brain: previously, the nerve cells in the mushroom body were linked only with learning and behaviour patterns that are based on learned associations. However, when the scientists temporarily disabled these nerve cells, hungry flies no longer showed any reaction whatsoever to carbon dioxide. The behaviour of fed flies, on the other hand, remained the same: they avoided the carbon dioxide.

In further studies, the researchers identified a projection neuron which transports the carbon dioxide information to the mushroom body. This nerve cell is crucial in triggering a flight response in hungry, but not in fed animals. "In fed flies, nerve cells outside the mushroom body are enough for flies to flee from the carbon dioxide. In hungry animals, however, the nerve cells are in the mushroom body and the projection neuron, which carries the carbon dioxide information there, is essential for the flight response. If mushroom body or projection neuron activity is blocked, only hungry flies are no longer concerned about the carbon dioxide," explains Ilona Grunwald-Kadow, who headed the study.

The results show that the innate flight response to carbon dioxide in fruit flies is controlled by two parallel neural circuits, depending on how satiated the animals are. "If the fly is hungry, it will no longer rely on the 'direct line' but will use brain centres to gauge internal and external signals and reach a balanced decision," explains Grunwald-Kadow. "It is fascinating to see the extent to which metabolic processes and hunger affect the processing systems in the brain," she adds.

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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Public release date: 25-Jun-2013
[ | E-mail | Share ]

Contact: Dr. Stefanie Merker
merker@neuro.mpg.de
49-898-578-3514
Max-Planck-Gesellschaft

Different neural circuits process environmental signals depending on the state of satiation

This news release is available in German.

Hungry people are often difficult to deal with. A good meal can affect more than our mood, it can also influence our willingness to take risks. This phenomenon is also apparent across a very diverse range of species in the animal kingdom. Experiments conducted on the fruit fly, Drosophila, by scientists at the Max Planck Institute of Neurobiology in Martinsried have shown that hunger not only modifies behaviour, but also changes pathways in the brain.

Animal behaviour is radically affected by the availability and amount of food. Studies prove that the willingness of many animals to take risks increases or declines depending on whether the animal is hungry or full. For example, a predator only hunts more dangerous prey when it is close to starvation. This behaviour has also been documented in humans in recent years: one study showed that hungry subjects took significantly more financial risks than their sated colleagues.

Also the fruit fly, Drosophila, changes its behaviour depending on its nutritional state. The animals usually perceive even low quantities of carbon dioxide to be a sign of danger and opt to take flight. However, rotting fruit and plants the flies' main sources of food also release carbon dioxide. Neurobiologists in Martinsried have now discovered how the brain deals with this constant conflict in deciding between a hazardous substance and a potential food source taking advantage of the fly as a great genetic model organism for circuit neuroscience.

In various experiments, the scientists presented the flies with environments containing carbon dioxide or a mix of carbon dioxide and the smell of food. It emerged that hungry flies overcame their aversion to carbon dioxide significantly faster than fed flies if there was a smell of food in the environment at the same time. Facing the prospect of food, hungry animals are therefore significantly more willing to take risks than sated flies. But how does the brain manage to decide between these options?

Avoiding carbon dioxide is an innate behaviour and should therefore be generated outside the mushroom body in the fly's brain: previously, the nerve cells in the mushroom body were linked only with learning and behaviour patterns that are based on learned associations. However, when the scientists temporarily disabled these nerve cells, hungry flies no longer showed any reaction whatsoever to carbon dioxide. The behaviour of fed flies, on the other hand, remained the same: they avoided the carbon dioxide.

In further studies, the researchers identified a projection neuron which transports the carbon dioxide information to the mushroom body. This nerve cell is crucial in triggering a flight response in hungry, but not in fed animals. "In fed flies, nerve cells outside the mushroom body are enough for flies to flee from the carbon dioxide. In hungry animals, however, the nerve cells are in the mushroom body and the projection neuron, which carries the carbon dioxide information there, is essential for the flight response. If mushroom body or projection neuron activity is blocked, only hungry flies are no longer concerned about the carbon dioxide," explains Ilona Grunwald-Kadow, who headed the study.

The results show that the innate flight response to carbon dioxide in fruit flies is controlled by two parallel neural circuits, depending on how satiated the animals are. "If the fly is hungry, it will no longer rely on the 'direct line' but will use brain centres to gauge internal and external signals and reach a balanced decision," explains Grunwald-Kadow. "It is fascinating to see the extent to which metabolic processes and hunger affect the processing systems in the brain," she adds.

###

---

[ | E-mail | Share ]

?

AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.

Source: http://www.eurekalert.org/pub_releases/2013-06/m-had062513.php

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House investigators: Disability judges too lax

WASHINGTON (AP) ? U.S. House investigators say Social Security is approving state-rejected claims for disability benefits at strikingly high rates for people who might not deserve them. Compounding the problem, the agency often fails to do required follow-up reviews to make sure people still qualify for benefits months or years later.

Claims for benefits have increased by 25 percent since 2007, pushing the fund that supports the disability program to the brink of insolvency. Social Security officials say the primary driver of the increase is a surge in baby boomers more prone to disabilities as they age but not quite old enough to qualify for retirement benefits.

Investigators from the House Oversight and Government Reform Committee say management problems also add to the financial problems of the cash-strapped program.

Source: http://news.yahoo.com/house-investigators-disability-judges-too-lax-182831645.html

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White House expects Russia to look at all options to expel Snowden back to U.S.

DEAR ABBY: I was taken away from my parents at 13 and placed into foster care, where I stayed until I aged out at 21. My biological mother is a drug addict who abandoned me to my father when I was 11. She never tried to contact me while I was in care.I am now 24 and she won't leave me alone. She sends Facebook messages that alternate between begging me to let her get to know me, and condemning me for being vindictive and not having forgiveness in my heart. Abby, this woman exposed me to drugs and all manner of seedy people and situations. ...

Source: http://news.yahoo.com/white-house-says-expects-russian-government-look-options-042146050.html

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New IRS chief: Inappropriate screening was broader

WASHINGTON (AP) ? The head of the Internal Revenue Service says inappropriate screening of groups seeking tax-exempt status was broader and lasted longer than was previously disclosed.

Danny Werfel told reporters Monday that after becoming acting IRS chief last month, he discovered inappropriate and wide-ranging criteria in lists screeners use to single out groups for careful examinations. He did not specify what terms were on the lists.

Werfel's comments suggest the IRS may have been targeting groups other than tea party and other conservative organizations for tough examinations to see if they qualify. The agency has been under fire since last month for targeting those groups.

Werfel said he has suspended use of those lists. Investigators have previously said agency officials abolished targeting of conservative groups in those lists in May 2012.

Source: http://news.yahoo.com/irs-chief-inappropriate-screening-broader-191736127.html

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AP PHOTOS: Supermoon looms bright in night sky

AAA??Jun. 23, 2013?12:06 AM ET
AP PHOTOS: Supermoon looms bright in night sky
By The Associated Press??By The Associated Press

The moon is seen in its waxing gibbous stage as it rises behind the helicopter from the original Batman television show, which people can ride at the New Jersey State Fair, Saturday, June 22, 2013, in East Rutherford, N.J. The moon, which will reach its full stage on Sunday, is expected to be 13.5 percent closer to earth during a phenomenon known as supermoon. (AP Photo/Julio Cortez)

The moon is seen in its waxing gibbous stage as it rises behind the helicopter from the original Batman television show, which people can ride at the New Jersey State Fair, Saturday, June 22, 2013, in East Rutherford, N.J. The moon, which will reach its full stage on Sunday, is expected to be 13.5 percent closer to earth during a phenomenon known as supermoon. (AP Photo/Julio Cortez)

A "supermoon" rises behind the Home Place clock tower in Prattville, Ala., Saturday, June 22, 2013. The biggest and brightest full moon of the year graces the sky early Sunday as our celestial neighbor swings closer to Earth than usual. While the moon will appear 14 percent larger than normal, sky watchers won't be able to notice the difference with the naked eye. Still, astronomers say it's worth looking up and appreciating the cosmos. (AP Photo/Dave Martin)

A "supermoon" rises behind roadside plants growing in Prattville, Ala., Saturday, June 22, 2013. The biggest and brightest full moon of the year graces the sky early Sunday as our celestial neighbor swings closer to Earth than usual. While the moon will appear 14 percent larger than normal, sky watchers won't be able to notice the difference with the naked eye. Still, astronomers say it's worth looking up and appreciating the cosmos. (AP Photo/Dave Martin)

A full moon rises beside the Bank of America corporate headquarters in downtown Charlotte, N.C., Saturday, June 22, 2013. The larger than normal moon called the "Supermoon" happens only once this year as the moon on its elliptical orbit is at its closest point to earth.(AP Photo/Chuck Burton)

A full moon rises beside an office building in downtown Charlotte, N.C., Saturday, June 22, 2013. The larger than normal moon called the "Supermoon" happens only once this year as the moon on its elliptical orbit is at its closest point to earth.(AP Photo/Chuck Burton)

Look up in the sky for a super sight: the biggest and brightest full moon of the year.

The so-called supermoon will appear 14 percent larger than normal early Sunday as our celestial neighbor swings closer to Earth. Some may think the supermoon looks more dazzling, but it's actually an optical illusion. The moon looms larger on the horizon next to trees and buildings.

The moon will come within 222,000 miles of Earth and turn full around 7:30 a.m. EDT, making it the best time to view.

Here are AP photos of the supermoon:

Associated Press

Source: http://hosted2.ap.org/APDEFAULT/386c25518f464186bf7a2ac026580ce7/Article_2013-06-23-Supermoon-Photo%20Gallery/id-bb752a8857ed42c3a807a141dea60fa9

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Are loli's playable here?

I know some sites don't allow you to play as them, for whatever reason. It's just well..they ARE popular in Japan in used a lot in anime...even games and as a canon player it annoys me a bit when sites restrict the kind of characters you can play. I'm not even talking for mature rps either. Granted lolis aren't my favorite but there are some I just find really funny (Like Squid Girl x3) and would like to play them but I just find it odd.

Now that I think on it, I know why...but it's still odd. I guess Japan just thinks of it differently, not that I am Japanese I just watch too much anime :P

Source: http://feedproxy.google.com/~r/RolePlayGateway/~3/Mb6NrGDiCnQ/viewtopic.php

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Snowden extradition battle in Hong Kong could go on for years

By James Pomfret

HONG KONG (Reuters) - A former U.S. National Security Agency (NSA) contractor charged with spying by the United States and in hiding in Hong Kong is expected to be the subject of a formal extradition request at any time in what could drag into a legal battle lasting years.

Since making his revelations about massive U.S. surveillance programs, legal sources in Hong Kong say Edward Snowden, 30, has sought legal representation from human rights lawyers as he prepares to fight U.S. attempts to force him home for trial.

U.S. authorities have charged Snowden with theft of U.S. government property, unauthorized communication of national defense information and willful communication of classified communications intelligence to an unauthorized person, with the latter two charges coming under the U.S. Espionage Act.

The United States and Hong Kong signed an extradition treaty which came into effect in 1998, a year after Hong Kong returned from British to Chinese rule. Scores of Americans have been sent back home for trial since then.

While espionage and theft of state secrets are not cited specifically in the treaty, equivalent charges could be pressed against Snowden under Hong Kong's Official Secrets Ordinance, legal experts said.

If Hong Kong authorities did not charge Snowden with an equivalent crime, authorities could not extradite him, lawyers said. In the absence of charges, Snowden was also theoretically free to leave the city, one legal expert said.

Simon Young, a law professor at the University of Hong Kong, said that while the first charge involving theft might readily find equivalence in Hong Kong, the latter two spying offences will likely attract "litigation and dispute" in the courts.

The timeframe for such proceedings remains unclear, but Hectar Pun, a lawyer with human rights expertise, was quoted as saying such an extradition could take three to five years.

Under Hong Kong's extradition mechanism, a request first goes through diplomatic channels to Hong Kong's leader, who decides whether to issue an "authority to proceed". If granted, a magistrate issues a formal warrant for the arrest of Snowden.

Once brought before the court, the judge would decide whether there was sufficient evidence to commit Snowden to trial or dismiss the case, though any decision could be appealed in a higher court.

Snowden could claim political asylum in Hong Kong, arguing he would face torture back home. Article six of the treaty states extradition should be refused for "an offence of a political character".

"The unfairness of his trial at home and his likely treatment in custody" were important factors to consider for Snowden, said Young, the law professor, on Snowden's chances of claiming political immunity from extradition.

Should a Hong Kong court eventually call for Snowden's extradition, Hong Kong's leader and China could, however, still veto the decision on national security or defense grounds.

Snowden has admitted leaking secrets about classified U.S. surveillance programs, which he said he did in the public interest. Supporters say he is a whistleblower, while critics call him a criminal and perhaps even a traitor.

(Editing by Nick Macfie)

Source: http://news.yahoo.com/hong-kong-silent-snowdens-fate-u-files-charges-041830621.html

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