The Protein for Quick Decision-Makers

Oct 26, 2009

(PhysOrg.com) -- Everyday, people are required to make decisions quickly and flexibly. In a flash, they must weigh up the advantages, disadvantages and possible consequences of their behaviour and coordinate it with the relevant external circumstances. This learning process involves the messenger substance dopamine.

Decisions that are perceived as positive and are followed by a reward trigger the increased release of dopamine and are recorded by the brain as beneficial. German researchers at the Max Planck Institute for Human Development have now discovered an enzyme variant that promotes fast and flexible decision-making behaviour.

It is known from previous studies that the COMT enzyme (cathecolamin-O-methyltransferase) breaks down dopamine and can, therefore, influence learning and thought processes. It is also known that there are two variants of the COMT enzyme (COMT Met and COMT Val) that influence dopamine levels to varying degrees. Lea Krugel and her colleagues from the Max Planck Institute for Human Development in Berlin investigated the question as to whether and how the influencing of the dopamine level by COMT-Met and COMT-Val in turn affects reward-dependent decision processes.

Individuals with the COMT-Val genotype learn faster from unexpected outcomes and are more flexible decision makers.

To this end, the scientists tested 26 who exhibited either only the Met variant or the Val variant of the COMT enzyme (Met/Met or Val/Val genotype). The study participants received a monetary bonus for their performance in reward-based decision tests which examined how quickly and flexibly they learned from the consequences of their actions. Decisions involving different options are often influenced by the expected reward. A significant difference between the result achieved and the expected outcome generates an important signal for the alteration of decision behaviour.

It emerged from the study that the participants with the Val version of the genotype were the more flexible decision makers and could better learn from the differences between outcomes and expectations. With the help of functional magnetic resonance imaging (fMRT), Lea Krugel and her colleagues were able to demonstrate that this advantage was accompanied by greater nerve cell activity in certain regions of the brain in which the messenger substance dopamine is known to play a particularly prominent role. Hence, the scientists observed greater activity in the region of the brain known as the striatum and more intensive interaction between the striatum and frontal lobe (prefrontal cortex) in the participants with the Val version of the COMT enzyme.

Based on this, the scientists not only demonstrated a possible advantage for individuals with the Val version of enzyme, which is the more common variant throughout the world than the Met version, their results also provide new clues as to how the messenger substance helps people to make use of past decisions for future ones in the context of ongoing decision-making processes.

More information: Lea K. Krugel, Guido Biele, Peter N. C. Mohr, Shu-Chen Li, Hauke R. Heekeren, Genetic Variation in Dopaminergic Neuromodulation Influences the Ability to Rapidly and Flexibly Adapt Decisions. Proceedings of the National Academy of Sciences (PNAS), October 12, 2009

Provided by Max-Planck-Gesellschaft (news : web)

Explore further: Novel marker discovered for stem cells derived from human umbilical cord blood

add to favorites email to friend print save as pdf

Related Stories

Genes may make some people more prone to anxiety

Aug 11, 2008

Inborn differences may help explain why trauma gives some people bad memories and others the nightmare of post-traumatic stress. Scientists in Germany and the United States have reported evidence linking genes to anxious ...

Recommended for you

New pain relief targets discovered

9 hours ago

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

Building 'smart' cell-based therapies

10 hours ago

A Northwestern University synthetic biology team has created a new technology for modifying human cells to create programmable therapeutics that could travel the body and selectively target cancer and other ...

Proper stem cell function requires hydrogen sulfide

13 hours ago

Stem cells in bone marrow need to produce hydrogen sulfide in order to properly multiply and form bone tissue, according to a new study from the Center for Craniofacial Molecular Biology at the Herman Ostrow School of Dentistry ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Doschx
not rated yet Oct 26, 2009
So some portion of wit, intelligence, and leadership is controlled by COMT enzyme producing genes. I wonder what the effect would be if this COMT-val enzyme was given in mass quantities to a... tiger or something. Smarter predator? or does the enzyme need to be produced internally for any benefit?

More news stories

Chronic inflammation linked to 'high-grade' prostate cancer

Men who show signs of chronic inflammation in non-cancerous prostate tissue may have nearly twice the risk of actually having prostate cancer than those with no inflammation, according to results of a new study led by researchers ...

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...