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MAOA-VNTR polymorphism modulates context-dependent dopamine release and aggressive behavior in males
Thorben Schlüter1, Oliver Winz2, Karsten Henkel1
1Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, 52074 Aachen, Germany.
Neuroimage
|October 21, 2015
Summary
Monoamine oxidase A (MAOA) gene variants influence dopamine release and aggression. MAOA-High individuals showed increased dopamine and aggression with violent stimuli, unlike MAOA-Low individuals.
Area of Science:
- Neuroscience
- Behavioral Genetics
- Psychiatry
Background:
- Dopamine synthesis rates correlate negatively with aggression.
- Monoamine oxidase A (MAOA) metabolizes dopamine and its gene variants are linked to aggression.
- The MAOA tandem repeat (VNTR) promoter polymorphism modulates MAOA expression and aggressive behavior.
Purpose of the Study:
- To investigate if MAOA VNTR variants influence dopamine release and aggression in response to violent stimuli.
- To examine the neurobiological mechanisms underlying aggression modulated by MAOA genotype.
Main Methods:
- Selected healthy male subjects with MAOA-High and MAOA-Low VNTR genotypes.
- Utilized positron emission tomography (PET) with [(18)F]DMFP to measure dopamine D2/3 receptor availability.
- Assessed aggressive behavior using the Point Subtraction Aggression Paradigm (PSAP) after viewing neutral and violent movies.
Main Results:
- MAOA-Low carriers exhibited higher aggression under neutral conditions.
- MAOA-High subjects showed increased dopamine release and aggression after viewing violent stimuli.
- MAOA-Low subjects displayed decreased aggression and no consistent dopamine release in response to violent stimuli.
Conclusions:
- The MAOA-promoter polymorphism may impact the neurobiological modulation of aggressive behavior.
- Findings suggest a complex interaction between MAOA genotype, dopamine, and aggression, not a simple pro-dopaminergic mechanism for MAOA-Low.
- This study provides insights into the genetic and neurobiological underpinnings of aggression.
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