Brain Protein May be Linked to Depression
(Washington, Associated Press,1/5/06)

Dr. Paul Greengard of Rockefeller University and team, along with researchers from Sweden's Karolinska Institute, studied the role of the p11 protein in controlling how brain cells respond to serotonin.  Scientists had already linked low levels of serotonin, a neurotransmitter, with depression and recent research had differentiated fourteen serotonin receptors. Greengard’s team investigated the role of p11 in increasing the number of 1B receptors on the surface of brain cells. The investigators discovered that mice bred to be genetically incapable of producing p11 protein have fewer 1B receptors and exhibit less serotonin activity and signs of depression. They also found that brain tissue from the autopsies of depressed people has substantially lower levels of p11 than usual. These findings suggest that treatments that boost p11 levels may protect against depression by increasing “1B” receptors and thereby .modulating serotonin activity.

(Science, January 2006)