In collaboration with Gary Lynch, PhD, and Eniko Kramar, PhD, also of the University of California , Irvine, Brunson and Baram found that communication between brain cells, considered to be the cellular basis for learning and memory, was faulty in the middle-aged rats. Recordings of the electrical activity of brain cells appeared normal in young adult rats exposed to early life stress, but became very disturbed as they reached middle age.
"Now that concrete deficits in brain cell communication have been found in the early-life stressed, demented rats, it may be feasible to find the specific molecules involved and design medicines to prevent the deficits," Baram says.
In other work, researchers showed in rats that stress during the last third of pregnancy affects the ability of adult offspring to respond to challenges to their immune system. Heather Richardson, PhD, and her colleagues Soon Lee, PhD; Dong Seo, PhD, and Catherine Rivier, PhD, at the Salk Institute in La Jolla, Calif., found that the changes in the offsprings' response to immune challenges may be due in part to deficits in nitric oxide, a signaling system in the brain known to connect the immune and stress systems.
Twenty-nine pregnant rats were exposed daily to one of two stresses during the last third of their pregnancies; controls in this group were left alone. Adult female offspring were
Contact: Leah Ariniello
Society for Neuroscience