Protein identified that may cause brain shrinking in depression

New Scientist : Dendrites relay messages between neurons. In brains of the severely depressed, they are significantly shrunken. This shrinking is considered to be the cause of some of the symptoms of depression. A protein, REDD1, was recently shown to reduce the production of myelin , a fatty material that protects neurons. Building on that finding, Ronald Duman of Yale University and his colleagues bred rats that didn’t produce REDD1 and exposed them to stresses. In response to the stress, normal rats became depressed, but Duman’s REDD1-less rats did not. And rats bred to overproduce the protein became depressed even without the stressing. Duman’s group also found a connection between the presence of stress hormones and the production of REDD1. Then, looking at postmortem human brain tissue, they found elevated levels of the protein in the brains of subjects who had suffered from depression. Duman suggests that directly targeting the production of REDD1 may be an effective way to treat depression.