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An image showing gene-brain-behavior relationship of male aggression has been selected as 2007 Image of the Year at SNM’s 54th Annual Meeting in Washington.

Whenever there is a publicized case of violent behavior, people ask the question, “Why?” An image—describing scientific investigation into the relationship between an individual’s brain chemistry and his report about his behavior toward others—has been selected as the 2007 Image of the Year at SNM’s 54th Annual Meeting in Washington, D.C. The image was chosen from thousands presented at the Annual Meeting, hosted by SNM, the world’s largest society for molecular imaging and nuclear medicine professionals.

“One of the major scientific contributions of molecular imaging is its ability to relate human brain chemistry and behavior,” said Henry N. Wagner Jr., SNM past president and historian, who announced the Image of the Year at the society’s press conference on June 4.

Scientists from Brookhaven National Laboratory have shown a statistical relationship between brain levels of the enzyme monoamine oxidase (MAO) A and the quantitative assessment of their human subjects’ personality.

“Researchers used the Tellegen and Waller Multidimensional Personality Questionnaire to measure the volunteers’ personality traits and the tracer C-11 clorgyline to measure enzymatic brain MAO A activity,” explained Wagner.

Of 240 questions, only those about having a short temper, vindictiveness and enjoying violent movies were related to MAO A, said Wagner, who for 30 years has summarized current trends in molecular imaging and nuclear medicine and the meeting’s significant findings and annually selects an Image of the Year.

“Many similar studies are likely to follow,” added the professor of environmental health sciences at Johns Hopkins University in Baltimore, Md. The Image of the Year—corroborating the relevance of brain enzyme MAO A in aggressive personality—is actually a series of four images: one providing a view of human genes with high and low concentrations of MAO A; one of a brain positron emission tomography (PET) scan showing brain MAO A activity; and two images of human aggression.

“The study is an example of how scientists are beginning to investigate the complex relationships between an individual’s biology and his behavior toward others,” said Nelly Alia-Klein, an assistant scientist at the Brookhaven Center for Translational Neuroimaging at Brookhaven National Laboratory in Upton, N.Y. Brookhaven is one of 10 national laboratories overseen and primarily funded by the U.S. Department of Energy’s Office of Science.

“After a publicized case of violence, we see and hear many stories about the aggressor’s behavior prior to the incident and his way of life and the relationships he had with other people. However, scientists agree that there are many reasons why and how people move from aggression to violence, which most of the time involved physical assault,” she added.

“Our study concentrated on how someone’s genetic and brain makeup can influence aggressive personality in healthy non-violent volunteers. Our major finding is that having more of the brain MAO A enzymatic activity is related to reporting less aggressive behavior in a personality questionnaire ” said Alia-Klein. She explained that for more than two decades, scientists have studied MAO in relation to aggressive and violent behavior.

Joanna S. Fowler, an SNM member, member of the National Academy of Sciences and a senior chemist at Brookhaven, developed a way to tag the MAO A enzyme and study its activity in the brain. “The healthy, non-violent men who volunteered to do our study had their MAO A brain activity captured by PET, a camera that uses molecules with special tags to map chemical activity in the brain,” explained Alia-Klein.

The men then answered a questionnaire that mapped their personality profile. “We discovered that the amount of MAO A activity in the brain of 27 healthy men corresponded to the amount of aggression they reported in the questionnaire,” said Alia-Klein. “The less MAO A they had in the brain, the more they answered ‘yes’ to statements about taking advantage of others and causing them discomfort,” she noted.

“Although the personality questionnaire gave a complete profile of the men’s personalities, only aggressive personality was related to brain MAO A activity—not other personality dimensions,” she emphasized.

“Our finding corroborates the relevance of brain MAO A in aggressive personality,” explained Alia-Klein. “If this model of understanding is tested on individuals who engage in violent behavior (e.g., domestic violence), it could show promise in the future for pharmacological intervention against abnormal violence,” she added.

Poster: N. Alia-Klein, E. Shumay, R.Z. Goldstein, A. Kriplani, J. Logan, F. Telang, G. Wang, F. Henn, N.D. Volkow, J.S. Fowler, Brookhaven Center for Translational Neuroimaging, Brookhaven National Laboratory, Upton, N.Y.; B. Williams, I. Craig, Psychological Medicine, Psychiatry, King's College, London, United Kingdom; and N.D. Volkow, National Institute on Drug Abuse, NIH, Bethesda, Md., 'Gene-Brain-Behavior Relationships: Evidence that Aggression Is Associated With Brain MAO A Activity in Healthy Males,' SNM’s 54th Annual Meeting, June 2–6, 2007, Scientific Poster 1194.