HENRY

The ability (or curse) for remembering traumatic memories appears to be linked to a deletion in ADRA2β, a gene that codes for an adrenergic neuroreceptor. The authors of A deletion variant of the alpha2b-adrenoceptor is related to emotional memory in Europeans and Africans (doi:10.1038/nn1945), first surveyed a large group of people; around 450 volunteers. The volunteers were shown a set of photos ranging in subject matter from cute puppies to accident scenes, and asked to rate them as being either emotionally positive, neutral, or negative. 10 minutes after the experiment, they were asked to describe the pictures. Strikingly, the people with the ADRA2β deletion had significantly better recall for the emotionally charged pictures.

Since this deletion was strongly linked to the recall of emotional memories, is it possible that this is a major problem when there are things that you need to forget? To investigate, this the authors investigated around 200 refugees who survived the Rwandan civil war, and, unsurprisingly, almost 70% met the diagnostic criteria for post-traumatic stress disorder. In accordance with the previous results, the refugees who had the ADRA2β deletion, where the ones who had the worst symptoms.

The authors conclude -

The present findings suggest that the price for the deletion-related enhancement of emotional memory may be enhanced intrusive and distressing emotional memory for traumatic events. Consistent with the idea that a genetically anchored alteration in the noradrenergic system is related to traumatic memory, recent studies have indicated that the noradrenergic system is a promising target for pharmacological treatment of PTSD.

ScienceNow also has some brief coverage. Update: and neurocritic has some more.

Posted on August 1st, 2007 by Simon Greenhill