Monoamine oxidase-a genetic variations influence brain activity associated with inhibitory control: new insight into the neural correlates of impulsivity.
BACKGROUND
Previous evidence has shown that genetic variations in the serotonergic system contribute to individual differences in personality traits germane to impulse control. The monoamine oxidase-A (MAO-A) gene, coding for an enzyme primarily involved in serotonin and noradrenaline catabolism, presents a well-characterized functional polymorphism consisting of a variable number of tandem repeats in the promoter region, with high-activity and low-activity variants. High-activity allele carriers have higher enzyme expression, lower amine concentration, and present higher scores on behavioral measures of impulsivity than low-activity allele carriers.


METHODS
We studied the relationship of this polymorphism to brain activity elicited by a response inhibition task (Go/NoGo task), using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging in 24 healthy men.


RESULTS
Direct comparison between groups revealed a greater BOLD response in the right ventrolateral prefrontal cortex (Brodmann's area [BA] 45/47) in high-activity allele carriers, whereas a greater response in the right superior parietal cortex (BA 7) and bilateral extrastriate cortex (BA 18) was found in low-activity allele carriers.


CONCLUSIONS
These data suggest that a specific genetic variation involving serotonergic catabolism can modulate BOLD response associated with human impulsivity.
Passamonti
Luca
L
Neurology Unit, Department of Neurosciences, University Politecnica delle Marche, Ancona, Italy.
Fera
Francesco
F
Magariello
Angela
A
Cerasa
Antonio
A
Gioia
Maria Cecilia
MC
Muglia
Maria
M
Nicoletti
Giuseppe
G
Gallo
Olivier
O
Provinciali
Leandro
L
Quattrone
Aldo
A
D000293:Adolescent; D000328:Adult; D000483:Alleles; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004247:DNA / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D018598:Minisatellite Repeats; D008995:Monoamine Oxidase / Q000235:genetics*; D010100:Oxygen / Q000097:blood; D011110:Polymorphism, Genetic / Q000235:genetics; D017397:Prefrontal Cortex / Q000503:physiopathology; D014793:Visual Cortex / Q000502:physiology
D004247:DNA; D008995:Monoamine Oxidase; D010100:Oxygen