Posts Tagged 'fear'

From the APS Journal Archive: Genetic Gating of Human Fear Learning and Extinction: Possible Implications for Gene-Environment Interaction in Anxiety Disorder

“Genetic Gating of Human Fear Learning and Extinction: Possible Implications for Gene-Environment Interaction in Anxiety Disorder” by Tina B. Lonsdorf1,2, Almut I. Weike3, Pernilla Nikamo4, Martin Schalling4, Alfons O. Hamm3,5 and Arne Öhman1,2,5 was published in Psychological Science in February 2009 and has been cited 53 times (via Web of Science) since publication.

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Pavlovian fear conditioning is a widely used model of the acquisition and extinction of fear. Neural findings suggest that the amygdala is the core structure for fear acquisition, whereas prefrontal cortical areas are given pivotal roles in fear extinction. Forty-eight volunteers participated in a fear-conditioning experiment, which used fear potentiation of the startle reflex as the primary measure to investigate the effect of two genetic polymorphisms (5-HTTLPR and COMTval158met) on conditioning and extinction of fear. The 5-HTTLPR polymorphism, located in the serotonin transporter gene, is associated with amygdala reactivity and neuroticism, whereas the COMTval158met polymorphism, which is located in the gene coding for catechol-O-methyltransferase (COMT), a dopamine-degrading enzyme, affects prefrontal executive functions. Our results show that only carriers of the 5-HTTLPR s allele exhibited conditioned startle potentiation, whereas carriers of the COMT met/met genotype failed to extinguish conditioned fear. These results may have interesting implications for understanding gene-environment interactions in the development and treatment of anxiety disorders.

1Department of Clinical Neuroscience, Psychology Section, Karolinska Institutet
2Stockholm Brain Institute, Stockholm, Sweden
3Department of Clinical and Biological Psychology, Ernst Moritz-Arndt University of Greifswald
4Department of Molecular Medicine and Surgery, Neurogenetics Unit, Karolinska Institutet
5Center for the Study of Emotion and Attention, University of Florida