If you’re scared of heights, flying or the neighbor’s dog, new research suggests you can blame one particular gene.The gene in question, called stathmin, appears to control the ability to learn and remember frightening experiences and recognize threatening situations. Such basic skills are considered critical to survival.The discovery in mice “firms up the ground from which we can continue to explore the how, when and why of fear conditioning,” said Mahzarin Banaji, a Harvard University professor of psychology.Banaji, who was not involved in the study, said “it gives us new confidence to explore how human beings may both over-respond and under-respond with fear to events in their world. And it creates a stronger bond between the genetics of fear and the psychological and social consequences of fear learning."Aiming to help people who suffer from anxiety disorders, a research team from Harvard Medical School, Columbia University, Rutgers University, and the Albert Einstein College of Medicine found that mice genetically engineered to go without stathmin had a reduced ability to react with anxiety in situations in which they would normally have been expected to be fearful.The finding may open doors to anti-anxiety treatments that target the stathmin gene."This is the tip of the iceberg, and these things take a lot of time, but I think there’s no question that this has the potential for therapy,” said 2000 Nobel prizewinner and study co-author Dr. Eric Kandel, of the Howard Hughes Medical Institute Center for Neurobiology and Behavior at Columbia University in New York City."There aren’t good drugs for the treatment of anxiety, and it’s possible that this will provide a new set of targets for all kinds of problems, ranging from stage fright and phobias to post-traumatic stress disorders,” Kandel added.Stathmin genes are found in high levels in an almond-shaped section of the brain known as the amygdala, a center for the regulation of emotions.In a series of experiments with mice, Kandel and his colleagues found that the normal presence of stathmin genes controlled a process of cellular breakdown and rebuilding that gives the brain the necessary flexibility to rapidly form neural connections critical to normal learning and memory processes.Reporting in the Nov. 18 issue of Cell, the researchers found this process was both overactive and less flexible in mutant mice bred without stathmin. This deficiency stripped their brains of critical neural “scaffolding,” and short-circuited their ability to learn new fear or to rely on instinctive fear when placed in typically anxiety-inducing situations.
