Gene x environment effect of serotonin transporter genotype and acute stressor on amygdala gene expression. Mus musculus

The amygdala is a prominent region of the brain processing stress-related emotion and vigilance. Additionally it is known that the serotonergic system is strongly involved in stress response and adaptation. The serotonin transporter (5-HTT) as key regulator of serotonergic activity in the brain is associated with stress-related neuropsychiatric disorders as well as heightened trait anxiety/dysphoria and exaggerated response to fear and environmental stress in humans. Also 5-HTT knockout mice display increased anxiety- and depression-related behaviors, altered stress reactivity and stress-coping abilities, gene expression differences and altered dendritic morphology. We measured immediate reactions to an acute stressor in 5-HTT knockout mice vs. wildtypes using microarrays for genome wide gene expression profiling in the amygdala and identified different functional clusters dependent on condition and genotype. Overall design: Global amygdalar gene expression profiles were compared between 5-HTT knockout vs. wildtype mice in the conditions control vs. acute stressor in a total sample of 20 (5 biological replicates per genotype and condition).