Hunger affects decision-making and perception of risk
June 25, 2013 — 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.
Welcome to SUV System Ltd!
SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.
We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.
SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com
Electronic Components distributor:http://www.suvsystem.com
Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html
IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html
LED Distributor:http://www.suvsystem.com/l/LED-1.html
Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html
Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html
Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html
Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html
SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc
we are focus on the following fields,and hope we can help you.
AT83SND2CMP3A1-7FTUL AT83R22OK106-RDTUM AT87C58X2-RLTUL AT87C58X2-3CSUM AT87C58X2-3CSUL AT87C54X2-SLSUM AT87C54X2-SLSUL AT87C54X2-SLRUM AT87C54X2-RLTUL AT87C54X2-3CSUM AT87C54X2-3CSUL AT87C52X2-SLSUV AT87C52X2-SLSUM AT87C52X2-SLSUL AT87C52X2-RLTUM AT87C52X2-RLTUL AT87C52X2-RLRUM AT87C52X2-3CSUM AT87C52X2-3CSUL AT87C51RD2-SLSUM AT87C51RD2-SLSUL AT87C51RD2-RLTUM AT87C51RD2-RLTUL AT87C51RD2-RDTUM AT87C51RD2-RDTUL AT87C51RD2-3CSUM AT87C51RD2-3CSUL AT87C51RC2-SLSUM AT87C51RC2-SLSUL AT87C51RC2-RLTUL AT87C51RC2-3CSUM AT87C51RC2-3CSUL AT87C51RB2-SLSUM AT87C51RB2-SLSUL AT87C51RB2-SLRUM AT87C51RB2-RLTUM AT87C51RB2-RLTUL AT87C51RB2-RLRUM AT87C51RB2-3CSUM AT87C51RB2-3CSUL
http://www.suvsystem.com/a/3209.aspx
