title: Brain monoamine oxidase A activity predicts trait aggression.
abstract: The genetic deletion of monoamine oxidase A (MAO A), an enzyme that breaks down the monoamine neurotransmitters norepinephrine, serotonin, and dopamine, produces aggressive phenotypes across species. Therefore, a common polymorphism in the MAO A gene (MAOA, Mendelian Inheritance in Men database number 309850, referred to as high or low based on transcription in non-neuronal cells) has been investigated in a number of externalizing behavioral and clinical phenotypes. These studies provide evidence linking the low MAOA genotype and violent behavior but only through interaction with severe environmental stressors during childhood. Here, we hypothesized that in healthy adult males the gene product of MAO A in the brain, rather than the gene per se, would be associated with regulating the concentration of brain amines involved in trait aggression. Brain MAO A activity was measured in vivo in healthy nonsmoking men with positron emission tomography using a radioligand specific for MAO A (clorgyline labeled with carbon 11). Trait aggression was measured with the multidimensional personality questionnaire (MPQ). Here we report for the first time that brain MAO A correlates inversely with the MPQ trait measure of aggression (but not with other personality traits) such that the lower the MAO A activity in cortical and subcortical brain regions, the higher the self-reported aggression (in both MAOA genotype groups) contributing to more than one-third of the variability. Because trait aggression is a measure used to predict antisocial behavior, these results underscore the relevance of MAO A as a neurochemical substrate of aberrant aggression.
authors.affiliation: Medical Department, Brookhaven National Laboratory, Upton, New York 11973, USA. nellyklein@bnl.gov
authors.forename: Nelly
authors.initials: N
authors.lastname: Alia-Klein
authors.forename: Rita Z
authors.initials: RZ
authors.lastname: Goldstein
authors.forename: Aarti
authors.initials: A
authors.lastname: Kriplani
authors.forename: Jean
authors.initials: J
authors.lastname: Logan
authors.forename: Dardo
authors.initials: D
authors.lastname: Tomasi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Williams
authors.forename: Frank
authors.initials: F
authors.lastname: Telang
authors.forename: Elena
authors.initials: E
authors.lastname: Shumay
authors.forename: Anat
authors.initials: A
authors.lastname: Biegon
authors.forename: Ian W
authors.initials: IW
authors.lastname: Craig
authors.forename: Fritz
authors.initials: F
authors.lastname: Henn
authors.forename: Gene-Jack
authors.initials: GJ
authors.lastname: Wang
authors.forename: Nora D
authors.initials: ND
authors.lastname: Volkow
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Fowler
mesh_terms: D000328:Adult; D000374:Aggression / Q000502:physiology* / Q000523:psychology; D000588:Amines / Q000378:metabolism; D001921:Brain / Q000201:enzymology*; D003010:Clorgyline; D006801:Humans; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors; D009994:Osmolar Concentration; D010551:Personality; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011795:Surveys and Questionnaires; D014018:Tissue Distribution
chemical_list: D000588:Amines; D008996:Monoamine Oxidase Inhibitors; D008995:Monoamine Oxidase; D003010:Clorgyline